ACS

अब Quizwiz के साथ अपने होमवर्क और परीक्षाओं को एस करें!

Which ion is the smallest? a) Al3+ b) Na+ c) F- d) O2-

Al3+

Which element has the highest electronegativity? a) cesium b) iodine c) oxygen d) lithium

oxygen

Alkaline earth metals form

+2 ions

A typical silicon chip, such as those in electronic calculators, has a mass of 2.3 x 10 ^ -4 g. Assuming the chip is pure silicon, how many silicon atoms are in the chip?

4.9 x 10 ^ 18 atoms

What is the ass percent of oxygen in Fe2(SO4)3?

48.01%

Which graph best represents the titration of ammonia with hydrochloric acid?

Which is the best Lewis structure for nitrogen monoxide?

The standard enthalpy of formation, delta H formation, for N02(g) is the enthalpy change for which reaction? A) N(g) + 20(g)----* NO2(g) B) 1/2N2(g) +O2 (g) ---> NO2(g) C) 1/2N2O4(g) --> NO2 (g) D) NO(g) + 1/2O2 (g) --> NO2(g)

B) 1/2N2(g) +O2 (g) ---> NO2(g)

Which set is not an allowed set of quantum numbers? A) 3,2,-1, 1/2 B) 4,0,-1, 1/2 C) 3,1,-1, -1/2 D) 4,0,0, -1/2

B) 4,0,-1, 1/2 with the l value of 0 the ml value of -1 is NOT allowed

Ibuprofen, a common pain reliever, contains 75.7 % carbon, 15.5% oxygen, and 8.80% hydrogen by mass. What is the empirical formula?

C13H18O2

Which ion has the largest radius? a) Cl- b) F- c) K+ d) Cu2+

Cl-

What is the strongest electrolyte in dilute aqueous solutions? a) HClO4 b) HCN c) HF d) HNO2

HClO4

What is a weak acid in water? a) HBr b) HCl c) HF d) HI

What is a main group element?

What is the resonance structure for the molecule shown?

if the formula of an ionic oxide of the element X2O3, what is the formula of the chloride of X?

XCl3

A 1.00 g sample of NH4N03 is decomposed in a bomb calorimeter. The temperature increases by 6.12 C. What is the molar heat of decomposition of NH4NO3? Table of Data NH4N03 80.0 g/mol calorimeter constant 1.23 kJ/C a) -602 kJ/mol b) -398 kJ/mol c) 7.53 kJ/mol d) 164 kJ/mol

a) -602 kJ/mol

Which atom or ion is paramagnetic in the ground state? a) Fe3+ b) Sc3+ c) Zn 2+ d) Ca

a) Fe3+

When a 45.0 g sample of an alloy at I00.0C is dropped into I 00.0 g of water at 25.0 °C, the final temperature is 37.0C. What is the specific heat of the alloy? a) 0.423 J/gC b) 1.77 J/gC c) 9.88 J/gC d) 48.8 J/gC

b) 1.77 J/gC

In which atom does a 2p electron experience the greatest effective nuclear charge, Zeff? a) B b) C c) F d) N

c) F

Which element is represented by 56 24 X?

chromium

Which sample contains the least number of atoms? a) 1.00 g C b) 1.00 g O2 c) 1.00 g H2 d) 1.00 g Fe

d) 1.00 g Fe has the least amount of atoms

The size of mental atoms

generally increases progressively from top to bottom in a group in the periodic table

Which group contains nonmetals, metalloids, and metals?

group 15

Which group number contains the most diatomic molecular elements?

group 17

A sodium ion different from a sodium atom in that the sodium ion

has fewer electrons

what is the classification of sulfur?

nonmetal

What happens when a bromine atom becomes a bromide ion?

the bromide ion is then larger than the bromine atom

Given the equilibrium constants for these reactions: 4Cu(s) + O2(g) --> 2Cu2O(s) Kc1 2CuO(s) --> Cu2O(s) + 1/2O2(g) Kc2 What is the value of Kc for this reaction? 2Cu(s) + O2 (g) --> 2CuO(s) (A) (square root of K1) / Kc2 (B) Kc2 / (square root of Kc1) (C) (square root of K1) x Kc2 (D) Kc1 x Kc2

(A)

Calculate the enthalpy of combustion of ethylene, C2H4, at 25C and one atmosphere of pressure. deltaHformation / kJ·mol-1 C2H4(g) 52.3 C02(g) -393.5 H20(l) -285.8 C2H4(g) + 302(g) --> 2C02(g) + 2H20(l) (A) -1411 kJ/mol (B) -1254 kJ/mol (C) -732 kJ/mol (D) -627 kJ/mol

(A) -1411 kJ/mol (2(-393.5) + 2(-285.8)) - 52.3)

What is the standard enthalpy change for this reaction? delta H formation / kJ·mol-1 HCl(aq) -167.2 MgCl2(aq) -641.6 Mg(s) + 2HCl(aq)---+ MgCl2(aq) + H2(g) (A) -307.2 kJ·mol-1 (B) 307.2 kJmol-1 (C) -474.4 kJ·mol-1 (D) 474.4 kJ·mol-1

(A) -307.2 kJ·mol-1

-549 kJ use the table to calculate the bond angle for each. subtract the bond energies of C2F6 from the sum of the bond energies for F2 and C2F4

(A) -856 kJ (B) -816 kJ (C) -549 kJ (D) -64 kJ

The solubility of carbon dioxide in water is very low in air ( 1.05x 10 ^ -5 M at 25 C) because the partial pressure of carbon dioxide in air is only 0.00030 atm. What partial pressure of carbon dioxide is needed to dissolve 100.0 mg of carbon dioxide in 1.00 L of water? (A) 0.0649 atm (B) 2.86 atm (C) 28.6 atm (D) 64.9 atm

(A) 0.0649 atm

A 250-mL bottle of a sports drink solution contains 4.50% by mass of sodium chloride. What is the molal concentration of sodium chloride in this bottle of sports drink? Molar mass NaCl 58.44 g/mol (A) 0.806 m (B) 0.770 m (C) 0.180 m (D) 0.0113 m

(A) 0.806 m

Phosgene decomposes into carbon monoxide and elemental chlorine. If the initial concentration of COCl2(g) is 0.50 M. what is the equilibrium concentration of CO(g)? COCl2 (g) -->CO(g) + Cl2 (g) Kc = 6.6x 10^-8 (A) 1.8x10-4 M (B) 9.1 X 10-5 M (C) 1.7x 10-8 M (D) 6.6x I0-8 M

(A) 1.8x10-4 M

Consider the reaction potential energy diagram. What describes the catalyzed forward reaction pathway? Ea deltaH (A) 10 kJ·mol-1 -15 kJ·moJ-1 (B) 10 kJ·mo1-1 15 kJ·moi-1 (C) 25 kJ·mol-1 -15 kJ·mol-1 (D) 25 kJ·mol-1 15 kJ·mol-1

(A) 10 kJ·mol-1 -15 kJ·moJ-1

A sample of gas occupies 3.00 L at 1.00 atm. What volume will it occupy at 1.45 atm and the same temperature? (A) 2.07 L (B) 4.35 L (C) 2280 L (D) 1572.4 L

(A) 2.07 L P1V1/T1 = P2V2/T2 temp stays the same P1V1 = P2V2 1.00 atm x 3L = 1.45 V2

The activation energy for a particular reaction is 83.1 kJ /mol. By what factor will the rate constant increase when the temperature is increased from 50.0 °C to 60.0 °C? (A) 2.53 (B) 1.00 (C) 0.927 (D) 0.395

(A) 2.53 k = Ae ^(-Ea/RT) -Ea = activation energy R = 8.314 J/mol K T= temp in K

What mass of water is needed to dissolve 292.5 g of NaCl to produce a 0.25 m aqueous solution? molar mass NaCl 58.44 g/mol (A) 20 kg (B) 5.0 kg (C) 0.80 kg (D) 0.050 kg

(A) 20 kg

The half-life for the first-order radioactive decay of 32P is 14.2 days. How many days would be required for a sample of a radiopharmaceutical containing 32P to decrease to 20.0% of its initial activity? (A) 33.0 d (B) 49.2 d (C) 71.0 d (D) 286 d

(A) 33.0 d

Which 0.1 molal aqueous solution will have the lowest freezing point? (A) Al(NO3)3 (B) CaCl2 (C) C2H5OH (D) NaCl

(A) Al(NO3)3

In non-aqueous solution, the trend in acid strength is observed to be: Ka (HI)> Ka (HBr) > Ka (HCl) Which periodic trend best explains this observed pattern? (A) Atomic radius: as the bond between H and the halogen becomes shorter, acid strength decreases (B) Electron affinity: as the halogen becomes more attracted to electrons, acid strength increases (C) Electronegativity: as the bond between the two atoms becomes less polar, acid strength decreases (D) Ionization energy: as it becomes harder to remove an electron from the halogen, acid strength increases

(A) Atomic radius: as the bond between H and the halogen becomes shorter, acid strength decreases

Which substance is acting as a Lewis acid? BF3 (g) + F- (g) --> BF4- (A) BF3 (B) F- (C) BF4- (D) This is not a Lewis acid-base reaction.

(A) BF3 lewis acids can accept an electron pair

What will be the effect of increasing the temperature of reactants that are known to undergo an endothermic reaction? (A) Both the rate of reaction and the value of the equilibrium constant increases. (B) The rate of reaction increases and the value of the equilibrium constant decreases. (C) The rate of reaction decreases and the value of the equilibrium constant increases. (D) The rate of reaction increases and the value of the equilibrium constant is unchanged.

(A) Both the rate of reaction and the value of the equilibrium constant increases.

What is the correct order of increasing normal boiling point of NaCI, Br2 and ICl? (A) Br2 < ICl < NaCl (B) ICl < Br2 < NaCl (C) NaCl < Brz < ICl (D) NaCl < ICl < Br2

(A) Br2 < ICl < NaCl as intermolecular forces increase, boiling point increases

Which substance has the lowest boiling point? (A) CH4 (B) CCl4 (C) CBr4 (D) CI4

(A) CH4

Which molecule contains carbon with a negative formal charge? (A) CO (B) CO2 (C) H2CO (D) CH4

(A) CO

Which molecule is nonpolar but contains polar bonds? (A) CO2 (B) SO2 (C) O2 (D) CH2Cl2

(A) CO2

Which anion is the most basic? (A) ClO- (B) ClO2 - (C) ClO3 - (D) ClO4 -

(A) ClO-

Which gas is most dense at 2 atm and 400K? (A) F2 (B) N2 (C) Ne (D) O2

(A) F2

Which substance will dissolve in water to produce an acidic solution? (A) FeCl (B) Na2O (C) NaC2H3O2 (D) NH3

(A) FeCl

Which molecule has the strongest nitrogen-nitrogen bond? (A) I (B) II (c) III (d) all are the same

(A) I

What changes when a catalyst is added to the reaction described by this energy diagram? (A) I and II (B) I and III (C)I only (D) III only

(A) I and II I is the activation energy for the reaction in the forward direction. II is the activation energy for the reaction in the reverse direction. III is the difference in energy of the reactants and products, which is the deltaH for the reaction. Because arrows I and II represent activation energies, these will be affected by the addition of a catalyst.

Consider the reaction Cl2(g) + H2S(aq)-> S(s) + 2H+(aq) + 2Cl-(aq) The rate equation for this reaction is rate= k[Cl2][H2S] Which mechanisms is (or are) consistent with this rate equation (if any)? I) Cl2 + H2S -> H+ + CI- + Cl+ + Hs- (slow) Cl+ + H2--> H+ + CI- + S (fast) II) H2S -> H+ + HS- (fast) Cl2 + HS- -> 2Cl- + H+ + S (slow) (A) I only (B) II only (C) Both I and II (D) Neither I or II

(A) I only

Consider pure water separated from an aqueous sugar solution by a semipermeable membrane. After some time has passed, what (if anything) will happen to the concentration of the sugar solution? (A) It will decrease. (B) It will increase. (C) It will remain the same. (D) It cannot be determined.

(A) It will decrease.

Consider the equilibrium reactions: 2SO2 (g) + O2 (g) --> 2SO3 (g). K1 2CO(g) + O2 (g) -->2CO2 (g). K2 What is the equilibrium constant, K, for this reaction? 2SO2 (g) + 2CO2 (g) --> 2SO3 (g) + 2CO(g) (A) K = (K1/K2) (B) K = (K2/K1) (C) K = K1 x K2 (D) K = K1 + (1/K2)

(A) K = (K1/K2)

What is the equilibrium expression for this reaction? Ni(CO)4 (g) --> Ni(s) + 4CO(g) (A) Kc = [CO]4 / [Ni(CO)4] (B) Kc = [Ni][CO]^4 / [Ni(CO)4] (C) Kc = [Ni(CO)4]/ [CO]^4 (D) Kc = [Ni(CO)4] / [Ni][CO]^4

(A) Kc = [CO]4 / [Ni(CO)4]

What is the Kp for this reaction? 2SO3 (g) --> 2SO2 (g) + O2 (g) (A) Kp= PSO2^2 PO2/ PSO3 ^2 (B) Kp = PSO2 PO2 / PSO3 (C) Kp = 2POS2 PO2 / 2PSO3 ^2

(A) Kp= PSO2^2 PO2/ PSO3 ^2

What are the Br0nsted-Lowry bases in this reaction? NH3 (aq) + H2O(aq) --> NH4 + (aq) +OH- (aq) (A) NH3 and OH- (B) H20 and NH4 + (C) NH3 and H3O + (D) NH4 + and OH-

(A) NH3 and OH-

Besides water molecules, what species is/are present at the greatest concentration when NH3(g) is bubbled into water? (Kb for NH3(aq) is 1.8x 10^-5) (A) NH3(aq) (B) NH40H(aq) (C) NH4+(aq) and OH-(aq) (D) NH2-(aq) and H30+(aq)

(A) NH3(aq)

In the laboratory, 50 mL of 0.1 M HCl is mixed with 50 mL of 0.1 M NaOH and the solution is stirred gently. At equilibrium, what ionic species, if any, will be present in large amounts in the reaction mixture? (A) Na+ and Cl- only (B) H3O+ and OH- only (C) H30+, OH-, Na+, and Cl- (D) no ions will be present

(A) Na+ and Cl- only

Which salt will form a basic aqueous solution? (A) NaF (B) KBr (C) LiCl (D) NH4NO3

(A) NaF

A central atom has two lone pairs and three single bonds. What is the molecular geometry? (A) T -shaped (B) tetrahedral (C) trigonal planar (D) trigonal pyramidal

(A) T -shaped

Which statement best explains why the activation energy is changed by adding a catalyst? (A) The catalyst changes the reaction mechanism. (B) The catalyst changes the free energy of reaction. (C) The catalyst increases the kinetic energy of the reactants. (D) The catalyst lowers the reaction volume, increasing the concentration of reactants.

(A) The catalyst changes the reaction mechanism.

The change in temperature from 10 °C to 20 °C is found to double the rate of a particular chemical reaction. How did the change in temperature affect the reaction? (A) The number of molecules with sufficient energy to react increased. (B) The number of molecules with sufficient energy to react decreased. (C) The activation energy increased. (D) The activation energy decreased

(A) The number of molecules with sufficient energy to react increased.

Suppose a gas mixture contains equal moles of He(g) and O2(g). Which is true? (A) The partial pressure of each gas is the same. (B) The partial pressure of He(g) is four times the partial pressure of O2(g). (C) The partial pressure O2(g) is two times the partial pressure of He(g). (D) The partial pressure of O2(g) is eight times the partial pressure of He(g).

(A) The partial pressure of each gas is the same. moles are used in partial pressure

Two reactions with different activation energies have the same rate at room temperature. Which statement correctly describes the rates of these two reactions at the same, higher temperature? (A) The reaction with the larger activation energy will be faster. (B) The reaction with the smaller activation energy will be faster. (C) The two reactions will continue to occur at the same rates. (D) A prediction cannot be made without additional information.

(A) The reaction with the larger activation energy will be faster.

An aqueous buffer solution contains only HCN (pKa = 9.31) and KCN and has a pH of 8.50. What can be concluded about the relative concentrations of HCN and KCN in the buffer? (A) [HCN] > [KCN] (B) [HCN] < [KCN] (C) [HCN] = [KCN] (D) nothing can be concluded about the relative concentrations

(A) [HCN] > [KCN]

The decomposition of hydrogen peroxide in the presence of iodide ion is believed to occur via this mechanism. H2O2(aq) + I-(aq)---+ H2O(l) + IO-(aq) H2O2(aq) + IO-(aq)---+ H2O(l) + O2(g) + I-(aq) In this mechanism, I-(aq) is (A) a catalyst. (C) the activated complex. (B) a reactant in the overall reaction. (D) a product of the overall reaction.

(A) a catalyst. the catalyst will always be on the product side of the fast step

Consider this equilibrium: 2SO2(g) + O2(g) --> 2SO3(g) The forward reaction is proceeding at a certain rate at some temperature and pressure. When the pressure is increased, what might we expect for the forward reaction? (A) a greater rate of reaction and a greater yield of SO3 at equilibrium (B) a greater rate of reaction and a same yield of SO3 at equilibrium (C) a lesser rate of reaction and a smaller yield of SO3 at equilibrium (D) a lesser rate of reaction and a greater yield of S03 at equilibrium

(A) a greater rate of reaction and a greater yield of SO3 at equilibrium You know that a change in pressure may shift the equilibrium and depends on the moles of gaseous substances as reactants and products. An increase in pressure will shift the equilibrium in the direction that minimizes the increase in pressure. This is the side that has the fewest moles of gas. For this reaction, the side with fewer moles of gas is the product side.

The Arrhenius equation describes the relationship between the rate constant, k, and the energy of activation, Ea. - Ae-Ea/RT In this equation, A is an empirical constant, R is the ideal-gas constant, e is the base of natural logarithms, and T is the absolute temperature. According to the Arrhenius equation, (A) at constant temperature, reactions with lower activation energies proceed more rapidly. (B) at constant temperature, reactions with lower activation energies proceed less rapidly. (C) at constant energy of activation, reactions at lower temperatures proceed more rapidly. (D) at constant energy of activation, reactions with smaller values of A proceed more rapidly.

(A) at constant temperature, reactions with lower activation energies proceed more rapidly.

A 10.0 mL portion of 0.010 M HCl is added to 100.0 mL of water. What is the pH of the resulting solution? (A) between 3.02 and 3.10 (B) between 2.90 and 3.01 (C) between 2.02 and 2.10 (D) between 1.90 and 2.01

(A) between 3.02 and 3.10 0.010 mol/L x .010 L = 0.001 0.001mol / .110 L = 0.000909091 -log(0.000909091)

The resonance structures for benzene indicate that the (A) bonds between carbons in benzene are identical. (B) benzene molecule exists as two unique structures. (C) benzene molecule alternates between forms I and II. (D) carbon-carbon single bonds are longer than the double bonds.

(A) bonds between carbons in benzene are identical.

A catalyst increases the rate of a reaction by (A) changing the mechanism of the reaction. (B) increasing the activation energy of the reaction. (C) increasing the concentration of one or more reactants. (D) decreasing the difference in relative energy of the reactants and products.

(A) changing the mechanism of the reaction.

Carbonated beverages have a fizz because of gas dissolved in the solution. What increases the concentration of gas in a solution? (A) cooling the solution (B) heating the solution (C) increasing the volume of solution (D) decreasing the volume of solution

(A) cooling the solution

For this equilibrium, what changes will favor formation of products? N2 (g) + 3 H2 (g) --> 2NH3 (g) deltaH = -92 kJ (A) decrease temperature, increase pressure (B) decrease temperature, decrease pressure (C) increase temperature, increase pressure (D) increase temperature, decrease pressure

(A) decrease temperature, increase pressure

According to MO theory, F2 would (A) have a bond order of 1 and be diamagnetic (B) have a bond order of 1 and be paramagnetic. (C) have a bond order of 2 and be diamagnetic. (D) have a bond order of 2 and be paramagnetic.

(A) have a bond order of 1 and be diamagnetic 1/2(10-8)=1 all electrons are paired

How will you increase the solubility of oxygen in water? The partial pressure of oxygen ( PO2) is 0.21 atm in air at 1 atm (Pext). (A) increase PO2 , but keep Pext constant (B) decrease PO2, but keep Pext constant (C) increase Pext but keep PO2 constant (D) decrease Pext but keep PO2 constant

(A) increase PO2 , but keep Pext constant

All gases approach ideal behavior under conditions of (A) low density and high temperature. (B) low density and low temperature. (C) high density and high temperature. (D) high density and low temperature.

(A) low density and high temperature. as volume increases, pressure decreases and gases exist the best at low pressures. as density is mass/volume, the greater the volume the smaller the density

SCl2 has ___ bonds and overall the molecule is ___ . (A) polar, polar (B) polar, nonpolar (C) nonpolar, polar (D) nonpolar, nonpolar

(A) polar, polar uneven distribution of valence electrons in Cl and S

Which solution has the higher boiling point? Solution: Molar mass (g/mol) (1) 200.0 g glucose dissolved in 1.00 kg of water glucose, 180 (2) 200.0 g sucrose dissolved in 1.00 kg of water sucrose, 342 (A) solution 1 (B) solution 2 (C) Both would boil at the same temperature as pure water. (D) Both would boil at the same temperature, but above that of pure water.

(A) solution 1 glucose has the higher m ΔTbp = Kbp msolute i ΔTbp = change in bp of the solvent Kbp = bp elevation constant (unique for each solvent) msolute = molality of the solute (mol solute/kg solvent) i = van't Hoff factor

What is the molecular geometry around theN atom in the molecule depicted? (A) t-shaped (B) tetrahedral (C) trigonal planar (D) trigonal pyramidal

(A) t-shaped

The Lewis dot structure of ethanol is given below. Estimate the enthalpy of combustion of ethanol (C2H5OH) using the bond enthalpies in the table. C2H5OH + 3O2 --> 2CO2 + 3H2O Bond enthalpy / kJ·moi-1 C-H 413 C-C 348 C-O 358 C=O 799 O-H 463 O=O 495 (A) + 1255 kJ-moJ-1 (B) -1255 kJ-moJ- 1 (C) -1509 kl-mol-1 (D) -2044 kJ·moJ-1

(B) -1255 kJ/mol

The combustion of ammonia is represented by this equation. delta H formation I kJ/mol NO(g) 90.3 H20(g) -241.8 4NH3(g) + 502(g)--> 4NO(g) + 6H20(g) delta H rxn = -904.8 kJ·mol-1 What is the standard enthalpy of formation of NH3(g)? (A) - 449 kJ/mol (B) -46.1 kJ/mol (C) -184 kJ/mol (D) -227 kJ/mol

(B) -46.1 kJ/mol 4(90.3) + 6(-241.8) = -1089.6 -1089.6 -(-904.8) = -184.8/4 = -46.1

Which aqueous solution will have the lowest osmotic pressure? (A) 0.04 M MgCl2 (B) 0.05 M KBr (C) 0.1 M LiCl (D) 0.2 M Na2SO4

(B) 0.05 M KBr osmotic pressure = icRT i = vont hoff factor c = concentration R = 8.314 J/K x mol T= temperature in K

If a 1.0 L flask is filled with 0.22 mol of N2 and 0.22 mol of O2 at 2000°C, what is [NO] after the reaction establishes equilibrium? (Kc = 0.10 at 2000°C) N2(g) + O2 (g) --> 2NO(g) (A) 0.034 M (B) 0.060 M (C) 0.079 M (D) 0.12 M

(B) 0.060 M

What is the mole fraction of water in 200. g of 89% (by mass) ethanol, C2H5OH? Molar Mass ethanol 46 g/mol (A) 0.11 (B) 0.24 (C) 0.32 (D) 0.76

(B) 0.24

Consider the reaction: X2 (g)+ 2Y(g) --> 2Z(g). 12.00 moles of Z are placed in an evacuated 2.00 liter flask. After the reactants and products reach equilibrium, the flask contains 6.00 moles of Y. What is the equilibrium constant, K, for the reaction? (A) 0.333 (B) 0.667 (C) 1.50 (D) 3.00

(B) 0.667 ice table

What is the bond order of the C-O bond in the acetate ion? (A) 1 (B) 1.5 (C) 2 (D) switches between 1 and 2

(B) 1.5 1/2 (6-3) 6 because there are 6 valence on C and 2 with the bond plus the negative change adds one electron

The pain reliever codeine is a weak base with a Kb equal to 1.6x 10^-6. What is the pH of a 0.05 M aqueous codeine solution? (A) 7.1 (B) 10.5 (C) 11.1 (D) 12.7

(B) 10.5

A 14.0 g sample of N2(g) occupies what volume at 0C and 1.00 atm? (A) 5.60 L (B) 11.2 L (C) 14.0 L (D) 22.4 L

(B) 11.2 L

A mixture of 3.25 moles of oxygen gas and 2.75 moles of nitrogen gas exert a total pressure of 22.4 atm. What is the partial pressure of oxygen? (A) 72.8 atm (B) 12.1 atm (C) 11.2 atm (D) 10.3 atm

(B) 12.1 atm 3.25 + 2.75 = 6 3.25/6 = 0.541 0.541 x 22.4

What mass of solid aluminum is needed to react with excess H2SO4(aq) to produce 20.0 L of H2(g) at 1.0 atm and 298 K? Molar Mass Al = 26.98 g/mol 2Al(s) + 3H2S04(aq)--> Al(S04)3(aq) + 3H2(g) (A) 0.545 g (B) 14.7 g (C) 22.0 g (D) 33.1 g

(B) 14.7 g

The pH of a 0.050 M aqueous solution of ammonium chloride (NH4Cl) falls within what range? (A) 0 to 2 (B) 2 to 7 (C) 7 to 12 (D) 12 to 14

(B) 2 to 7

In which case does Kc = Kp? (A) 2A(g) + B(s) --> 2C(s) + D(g) (B) 2A(g) + B(s) --> C(s) + 2D(g) (C) 3A(g) + B(s) --> 2C(s) + 2D(g) (D) Kc and Kp are equivalent in more than one of the above

(B) 2A(g) + B(s) --> C(s) + 2D(g)

Which reaction represents delta H formation for Al03(s)? (A) 4Al(s) + 302(g)----* 2Al203(s) (B) 2Al(s) + 3/202(g)----* Al203(s) (C) 2Al(s) + 30(g)----* Al203(s) (D) Al2(s) + 03(g)----* Al203(s)

(B) 2Al(s) + 3/202(g)----* Al203(s)

The density of a 3.539 M HN03 aqueous solution is 1.150 g/mL at 20C. What is the molal concentration? Molar Mass HNO3 63.02 g/mol (A) 3.077 m (B) 3.818 m (C) 3.946 m (D) 5.252 m

(B) 3.818 m

What volume of oxygen gas, measured at 27 C and 0.987 atm, is produced from the decomposition of 67.5 g of HgO( s )? Molar mass of HgO = 216.59 g/mol 2HgO(s)-+ 2Hg(l) + O2(g) (A) 3.49 L (B) 3.89 L (C) 6.98 L (D) 7.77 L

(B) 3.89 L 67.5 g x 1 mol/ 216.59 g = 0.3116 mol 0.3116 mol HgO x 1 mol O2/ 2 mol HgO = V = nRT/P

What volume (in mL) of 0.150 M NaOH(aq) is required to neutralize 25.0 mL of 0.100M H2SO4(aq)? (A) 16.7 mL (B) 33.3 mL (C) 66.7 mL (D) 75.0 mL

(B) 33.3 mL 2NaOH( aq) + H2SO4 ( aq) -->2H2O(l) + Na2SO4 ( aq)

For the nitrate ion, NO3-, predict the bond energy between nitrogen and the oxygen labeled "A". Bond enthalpy/ kJ/mol N-O 222 N=O 590 (A) 222 kJ.mol-1 (B) 345 kJ.mol-1 (C) 590 kJ·mol-1 (D) 812 kJ . mo, -1

(B) 345 kJ.mol-1

How many covalent bonds are represented in the formula NH4CI? (A) 5 (B) 4 (C) 1 (D) 0

(B) 4

A solution was made by adding 800 g of ethanol, C2H5OH, to 8.0x10 ^3 g of water. How much would this lower the freezing point? Kf °C/m H2O. 1.86 (A) 3.2 °C (B) 4.1 °C (C) 8.2 °C (D) 16 °C

(B) 4.1 °C

After 55 years, what mass (in g) remains of a 200.0 g sample of a radioactive isotope with a half-life of 10.0 years? (A) 0.22 g (B) 4.4 g (C) 51 g (D) 170 g

(B) 4.4 g

What is the approximate pKa of the weak acid in the titration curve? (A) 2.0 (B) 4.8 (C) 8.8 (D) 11.0

(B) 4.8 happens at the half of the equivalence point

What is the pH of a buffer solution containing equal volumes of 0.11 M NaCH3COO and 0.090 M. CH3COOH? Ka (CH3COOH) = 1.8x 10^-5 (A) 2.42 (B) 4.83 (C) 11.58 (D) 13.91

(B) 4.83

What is a true statement about Lewis acids and bases? (A) A Lewis acid must have a nonbonding (lone) pair of electrons. (B) A Lewis base must have a nonbonding (lone) pair of electrons. (C) In a Lewis acid-base reaction, a pair of electrons is donated from the acid to the base. (D) In a Lewis acid-base reaction, one species always goes from having a charge to being electronically neutral.

(B) A Lewis base must have a nonbonding (lone) pair of electrons.

What is the hybridization of the indicated nitrogen atoms? (A) A is sp; B is sp2 (B) A is sp2; B is sp3 (C) A is Sp2 ; B is sp2 (D) A is sp3; B is sp3

(B) A is sp2; B is sp3

Methyl orange is an indicator that changes color from red to yellow-orange over the pH range from 2.9 to 4.5. Methyl orange would be the most appropriate indicator for which type of acid -base titration? (A) A weak acid titrated with a strong base (B) A weak base titrated with a strong acid (C) A strong acid titrated with a strong base (D) Methyl orange would not be an appropriate indicator for any acid-base titration.

(B) A weak base titrated with a strong acid

If the diagram shown is representative of the particles in a sample of ideal gases, which statement is true? (A) A has the largest partial pressure. (B) B has the largest partial pressure. (C) C has the largest partial pressure. (D) All partial pressures are equal.

(B) B has the largest partial pressure. B has the most dots, equate that to having the most moles

Which pair of compounds would be the best choice to make a buffer solution with a pH around 5? (A)HF and NaF Ka = 6.9x10-4 (B) C2H4CO2H and C2H5CO2Na Ka = 1.3 x 10-5 (C)HClO and NaClO K. = 2.8x I0-8 (D) NH4Cl and NH3 Ka = 5.6xl0-10

(B) C2H4CO2H and C2H5CO2Na Ka = 1.3 x 10-5 pka = 4.74 so close to 5?

When the reaction: CH3Cl(g) + H2O(g) ----> CH3OH(g) + HCI(g) was studied, the tabulated data were obtained. Based on these data, what are the reaction orders? (A) CH3Cl : first order H2O: first order (B) CH3Cl : first order H2O: second order (C) CH3Cl: second order H2O: first order (D) CH3Cl: second order H2O: second order

(B) CH3Cl : first order H2O: second order

Arrange CsBr, NaCI, and RbBr in increasing magnitude oflattice energy. (A) CsBr < NaCl < RbBr (B) CsBr < RbBr < NaCI (C) NaCl < RbBr < CsBr (D) RbBr < CsBr < NaCI

(B) CsBr < RbBr < NaCI

Arrange LiF, HCI, HF, and F2 in order of increasing normal boiling point (A) F2 < HF < HCI < LiF (B) F2< HCI < HF < LiF (C) F2< HCI < LiF < HF (D) HF < LiF < HCl < F2

(B) F2< HCI < HF < LiF

Which set represents a conjugate acid/base pair? (A) HClO/HClO2 (B) H2PO4 - / HPO4 ^2- (C) H3O+ / OH- (D) NCl3 / NCl2 ^-

(B) H2PO4 - / HPO4 ^2-

In a 10.0 L vessel at 100.0 °C, 10.0 grams of an unknown gas exert a pressure of 1.13 atm. What is the gas? Gas Molar mass (g/mol) (A) NH3 17 (B) HCN 27 (C) NO 39 (D) N02 46

(B) HCN 27

What is the relationship between the equilibrium constant (Kc) of a reaction and the rate constants for the forward (kf) and reverse (kr) reactions in a single step reaction? (A) Kc = KfKr (B) Kc = kf/kr (C) Kc = 1/(kfkr) (D) Kc = kf - kr

(B) Kc = kf/kr

The gases, F2, H2, N2, and O2 at STP are represented in the plot. Which gas corresponds to curve III? (A) O2 (B) N2 (C) H2 (D) F2

(B) N2

Consider this reaction carried out at constant volume. 2SO2 (g)+ O2 (g)~ 2SO3 (g) deltaH = -198 kJ The concentration of O2(g) at equilibrium increases if (A) SO2 is added to the system. (B) SO3 is added to the system. (C) the temperature of the system is lowered. (D) an inert gas is added to the system.

(B) SO3 is added to the system.

The equilibrium constant, Kc = 3.8x I0-5 for the reaction, I2 (g)--> 2I(g) What is the state of the system if [I2(g)] = 1.0 M and [I(g)] = 1.0 x10^-3 M? (A) The system is at equilibrium. (B) The system is shifting towards products. (C) The system is shifting towards reactants. (D) There is insufficient information to describe the status of the system .

(B) The system is shifting towards products.

Which sample deviates most from ideal gas behavior? (A) Xe at 1 atm and -50 °C (B) Xe at 200 atm and -50 C (C) He at 200 atm and -50 C (D) Xe at 200 atm and 1000 C

(B) Xe at 200 atm and -50 C ideal temp of a gas is 273 K, 0C ideal pressure is 1 atm for noble gases, a relatively low temperature and high pressure would satisfy the "sufficiently" high temperature or "sufficiently" low pressure or density varies depending on the gas. And Xe is heavier than He

Which pair could be used to make a buffer solution? (A) acetic acid and sodium chloride (B) acetic acid and sodium hydroxide (C) hydrochloric acid and potassium chloride (D) hydrochloric acid and sodium hydroxide

(B) acetic acid and sodium hydroxide

The rate law for the reaction A+B---->C+D is first order in [A] and second order in [B]. If [A] is halved and [B] is doubled, the rate of the reaction will (A) remain the same. (B) be increased by a factor of 2 (C) be increased by a factor of 4. (D) be increased by a factor of 8.

(B) be increased by a factor of 2

Which substance is most soluble in water? (A) ethane, CH3CH3 (B) ethanol, CH3CH2OH (C) n-butane, CH3CH2CH2CH3 (D) !-butanol, CH3CH2CH2CH2OH

(B) ethanol, CH3CH2OH

The experimental data from a certain reaction gives these three graphs. What is the most likely order for this reaction? (A) zero (B) first (C) second (D) third

(B) first

The value for the rate constant of a reaction can generally be expected to (A) decrease with increasing temperature. (B) increase with increasing temperature. (C) decrease with increasing temperature only when the reaction is exothermic. (D) increase with increasing temperature only when the reaction is exothermic

(B) increase with increasing temperature.

As intermolecular forces increase, enthalpy of vaporization ____ and vapor pressure ___ _ (A) increases; increases (B) increases; decreases (C) decreases; increases (D) decreases; decreases

(B) increases; decreases

At 298 K, the equilibrium constant for this reaction H2(g) + 1/2O2(g) --> H2O(l) delta G formation (kj/mol) H2O(l). -237 H2O (g) -229 (A) has a value of 1.0 at equilibrium. (B) is larger than the Keq for H2 (g)+ 1/2O2 (g)--> H2O(g). (C) cannot be computed since data on O2 and H2 are not provided. (D) will have the same value as the Keq for H2 (g) + 1/2O2(g) --> H2O(g)

(B) is larger than the Keq for H2 (g)+ 1/2O2 (g)--> H2O(g). more negative delta G of formation means larger equilibrium constant

Consider the structure of Vitamin A1 (C20H30O). Vitamin A1 should be (A) insoluble in water and in oil (B) less soluble in water than in oil (C) equally soluble in water and in oil. (D) more soluble in water than in oil.

(B) less soluble in water than in oil

What will increase the value of the rate constant for an elementary step? (A) adding a catalyst (B) raising the temperature (C) increasing the concentration of products (D) increasing the concentration of reactants

(B) raising the temperature

The reaction between acetone and bromine in acidic solution is represented by the equation: CH3COCH3(aq) + Br2(aq) + H3O+(aq)----> products The tabulated kinetic data were gathered. Based on these data, the experimental rate law is (A) rate= k[CH3COCH3][Br2][H3O+] (B) rate= k[CH3COCH3][H3O+] (C) rate = k[H3O+] ^2 (D) rate= k[CH3COCH3][Br2]

(B) rate= k[CH3COCH3][H30+]

Initial rate data for the reaction 2H2(g) + Cl2(g) ----> 2HCI(g) are given in the table. What is the rate law for the reaction? (A) rate= k[Cl2]^2 (B) rate= k[Cl2] (C) rate= k[H2] (D) rate=k[H2][Cl2]

(B) rate= k[Cl2]

What is the rate law of this reaction? 2H2(g) + 2NO2(g) --> N2(g)+ 2H2O (g) Trial# [H2]/M [NO]/M Initial rate I M·s-1 1 1.0x 10-3 1.0 x 10-3 2.0x 103 2 2.0x 10-3 2.0x10-3 1.60x 104 3 2.0x 10-3 1.0x 10-3 4.0x103 (A) rate= k[H2]2[NO] (B) rate= k[H2][NO]2 (C) rate = k[H2]2[NO]2 (D) rate= k[N2][H2O]2/[H2]2[NO]2

(B) rate= k[H2][NO] 2

Which will drive the equilibrium to form more Cu(s)? Cu2O( s) + CO(g) --> 2Cu(s) + CO2 (g) (A) remove CO(g) (B) remove CO2(g) (C) add a catalyst (D) increase the volume of the container

(B) remove CO2(g) removal of a product will lead to the formation of more of the other product

What is the hybridization on the central atom in the molecule GeCl2? (A) sp (B) sp2 (C) sp3 (d) sp3D

(B) sp2 steric number is = 3 = sp2 steric number is number of bonds on central atom + number of lone pairs on central atom

The solubility of a substance is 60 g per 100 mL of water at 15C. A solution of this substance is prepared by dissolving 75 g in 100 mL of water at 75C. The solution is then cooled slowly to 15C without any solid separating. The solution is (A) supersaturated at 75°C. (B) supersaturated at 15°C. (C) unsaturated at 15°C. (D) saturated at 15°C

(B) supersaturated at 15°C.

What is the formal charge on the nitrogen atom in nitric acid, HN03? (A) -1 (B) 0 (C) +1 (D) +5

What is the Delta H of formation for the reaction CH4 (g) + 2O2(g) --> CO2(g) + 2H2O (l) delta H of formation = -890.3 kJ/mol 2CO(g) + O2(g) --> 2CO2(g) delta H of formation = -566.0 kJ/mol 2CH4(g) + 3O2(g) --> 2CO(g) + 4H2O(l) (A) -2346.6 kJ/mol (B) -1456.3 kJ/mol (C) -1214.6 kJ/mol (D) -324.3 kJ/mol

Use the standard enthalpies of formation in the table to calculate deltaHrxn for this reaction. deltaHformation /kJ·moi-1 CrO4 ^(2-) (aq) -881.2 Cr2O7 ^(2-)(aq) -1490.3 H+ 0 H2O(l) -285.8 2CrO4 ^(2-)(aq) + 2H+(aq)--> Cr2O7 ^(2-) (aq) + H20(l) (A) 272.1 kJ/mol (B) 13.7 kJ/mol (C) -13.7 kJ/mol (D) -272.1 kJ/mol

Given these values of delta H of formation in the table, what is the value of delta H of formation for the reaction? CS2(l) + 302(g) ----* CO2(g) + 2SO2(g) delta H formation = -1077 kJ/mol H2(g) + O2(g) --> H2O2(l) delta H formation = -188 kJ/mol H2(g) + 1/2 O2(g) ----* H2O(l) delta H formation - -286 kJ/mol CS2(l) + 6H202(l) ---->CO2(g) + 6H20(1) + 2SO2(g) (A) -1175 kJ/mol (B) -1151 kJ/mol (C) -1665 kJ/mol (D) -3921 kJ/mol

What is the delta H formation for this reaction? delta H formation / kJ·moi-1 Ag + (aq) 105.6 Hg2+(aq) 171.1 Hg(l) + 2Ag+(aq)--> Hg2+(aq) + 2Ag(s) (A) 65.5 kJ·mol-1 (B) 40.1 kJ·mol-1 (C) -40.1 kJ-mol-1 (D) -65.5 kJ·mol-1

Use the given heats of formation to calculate the enthalpy change for this reaction delta H formation/ kJ·mol-1 B2O3(g). -1272.8 COCl2(g). -218.8 CO2(g). -393.5 BCl3(g) -403.8 B2O3(g) + 3COCl2(g)--> 2BCl3(g) + 3CO2(g) (A) 649.3 kJ·mol-1 (B) 354.9 kJ-mol-1 (C) -58.9 kJ ·mol-1 (D) -3917.3 kJ·mol-1

Using the given thermochemical data, what is the delta H formation for this reaction? delta H formation / kJ·moi-1 CH30H(l). -238 HC2H302(1) -487 H20(l) -286 2CH3OH(l) + O2(g)--> HC2H3O2(1) + 2H2O(l) (A) 583 kJ ·mol-1 (B) 535 kJ·mol-1 (C) -583 kJ-mol-1 (D) -535 kJ ·mol-1

The decomposition of NOCl is second order. 2NOCl(g)--> 2NO(g) + Cl2(g) The initial concentration of the reactant is 0.050 M. The rate constant equals 0.020 L·mol-I.s-1, what will the concentration be after 45 min? (A) 0.048 M (B) 0.029 M (C) 0.014 M (D) 0.0054 M

What is the hydroxide ion concentration in an aqueous solution with a pH of 7.0 at 25 °C? (A) 0.0 M (B) 1.0 x 10-14 M (C) 1.0 x 10-7 M (D) 7.0 M

BrCl(g) is in equilibrium with Br2(g) and Cl2(g) at 25.0 °C: 2BrCl(g) ~ Br2 (g) + Cl2 (g) Kp = 0.130 Initially, in a closed container at 25.0 °C, BrCl(g) has a partial pressure of 0.400 atm and Br2(g) and Cl2(g) each have partial pressures of 0.800 atm. What is the partial pressure of BrCl(g) once the system reaches equilibrium? (A) 0.419 atm (B) 0.781 atm (C) 1.16 atm (D) 1.21 atm

What is the density of F2(g) at 1.00 atm and 25.0 °C? (A) 0.776 g/L (B) 0.850 g/L (C) 1.55 g/L (D) 1.70 g/L

What is the pH of a 0.820 M aqueous NH3 solution? Kb (NH3) = 1.8x 10 ^ -5 (A) 2.42 (B) 9.25 (C) 11.58 (D) 13.91

What is the density of Xe gas at 70 C and 2.50 atm? (A) 1.87 g·L-1 (B) 4.69 g·L -1 (C) 11.7g-L-1 (D) 57.1 g·L-1

What is the pH of a 0.053 M solution of KOH at 25 °C? (A) 0.89 (B) 1.28 (C) 12.72 (D) 13.11

How many sigma (cr) and pi (n) bonds are in one molecule of benzoic acid? (A) II sigma (cr), 4 pi (n) (B) II sigma (cr), 8 pi (n) (C) 15 sigma (cr), 4 pi(n) (D) 15 sigma (cr) , 8 pi(n)

How many lone pairs are on the central atom of ClF3? (A) 0 (B) 1 (C) 2 (D) 3

Using the MO diagram given to the right, what is the bond order for [N2]-? (A) 1.5 (B) 2 (C) 2.5 (D) 3

What is the pH of a buffer solution made by adding 0.010 mole of solid NaF to 50. mL of 0.40 M HF? Assume no change in volume. Ka (HF) = 6.9xl0-4 (A) 1.6 (B) 1.9 (C) 2.9 (D) 3.2

How many valence electrons are in the carbonate ion, CO3 ^2-? (A) 20 (B) 22 (C) 24 (D) 32

(C) 24 Oxygen has 6 valence electrons Carbon has 4 valence electrons 6x3 = 18 18 +4 =22 2 electrons because of charge 22 + 2 = 24

What is the enthalpy change for the reaction: N2O5(g) + H2O (l) --> 2HNO3(l) delta H of formation = -76.7 kJ/mol 2H2(g) + O2 --> 2H2O(l) delta H of formation -572 kJ/mol N2(g) + 3O2 + H2---> 2HNO3(l) delta H of formation = -348 kJ/mol 2N2(g) + 502(g) ----* 2N2O5(g) (A) -977 kJ/mol (B) -543 kJ/mol (C) 29 kJ/mol (D) 277 kJ/mol

A 10.0 L sample of an ideal gas at 25.0 C is heated at constant pressure until the volume has doubled. What is the final temperature of the gas? (A) 50.0C (B) 149 C (C) 323 C (D) 596 C

The activity of a radioisotope is 3000 counts per minute at one time and 2736 counts per minute 48 hours later. What is the half-life, in hours, of the radioisotope? (A) 831 hr (B) 521 hr (C) 361 hr (D) 1.44 hr

Aluminum metal crystallizes in a face-centered cubic unit cell. How many aluminum atoms are in one unit cell? (A) 14 (B) 7 (C) 4 (D) 2

A 2.50 g sample of naphthalene, C10H8, was dissolved in 100 g of benzene. What is the freezing point of the benzene solution? The freezing point of pure benzene is 5.45 °C; Kf = 5.07 °C·m-1. Molar Mass C10H8 128.17 g/mol (A) -0.989C (B) 0.989 C (C) 4.46 C (D) 6.44 C

Given the reaction and equilibrium constant: 2SO3 (g) --> 2SO2 (g)+ O2 (g) Kc = 2.3 X 10-7 What is the equilibrium constant for this reaction at the same temperature? SO3 (g)--> SO2 (g)+ 1/2O2 (g) Kc=? (A) 1.2x10-7 (B) 4.6x 10-7 (C) 4.8x 10-4 (D) 4.3x 106

An acetate buffer contains equal volumes of 0.35 M HC2H3O2 (pK. = 4.74) and 0.55 M NaC2H3O2. What is the pH of the buffer? (A) 4.54 (B) 4.74 (C) 4.94 (D) 7.00

One way to produce H2 for fuel cells is to react methane with steam. How much energy (in kJ) is needed to produce one mole of hydrogen gas using this reaction CH4 (g) + H2O --> CO(g) +3H2 (g) delta H of formation = 206 kJ/mol CO(g) + H2O(g) --> CO2(g) +H2 delta H of formation = -41.2 kJ.mol CH4(g) + 2H2O(g)----* CO2(g) + 4H2(g)? (A) -165 kJ (B) -41.2 kJ (C) 41.2kJ (D) 165 kJ

Vanadium (V) crystallizes in a body-centered cubic lattice with a unit cell edge length of 305 pm. What is the density of vanadium? (A) 1.49 g/cm3 (B) 2.98 g/cm3 (C) 5.96 g/cm3 (D) 11.9 g/cm3

What is the enthalpy of formation of hydrazine, N2H4(l)? deltaH formation / kJ/mol NH3(g) -46.3 3N2H4(l)--> 4NH3(g) + N2(g) delta H rxn = -336 kJ-mol-1 (A) -521 kJ·mol-1 (B) -112 kJ-mol-1 (C) 50.3 kJ-mol (D) 290 kJ-mol-1

The half-life for the first order conversion of cyclobutene to ethylene, C4H8(g) ---->2C2H4(g) is 22.7 s at a particular temperature. How many seconds are needed for the partial pressure of cyclobutane to decrease from 100 mmHg to 10 mmHg? (A) 0.101 s (B) 52.0 s (C) 75.5 s (D) 5233 s

What is the pH of a 0.400 M sodium formate (NaCHO2) solution? Ka (HCHO2) = 1.8x10-4 (A) 2.07 (B) 5.33 (C) 8.67 (D) 11.93

What is the pH of a solution that results from mixing 25.0 mL of 0.200 M HA with 12.5 mL of 0.400 M NaOH? (Ka = 1.0x 10 -5) (A) 2.94 (B) 4.94 (C) 9.06 (D) 11.06

Which statement most accurately describes the behavior of a catalyst? (A) A catalyst increases deltaG of a reaction and hence the forward rate. (B) A catalyst reduces the deltaH of a reaction and hence the temperature needed to produce products. (C) A catalyst reduces the activation energy for a reaction and increases the rate of a reaction. (D) A catalyst increases the equilibrium constant and final product concentrations.

Which statement best describes general equilibrium? (A) Equilibrium is reached when the reaction stops (B) There is only one set of equilibrium concentrations that equals the Kc value. (C) At equilibrium, the rate of the forward reaction is the same as the rate of the reverse reaction. (D) At equilibrium, the total concentration of products equals the total concentration of reactants.

According to kinetic-molecular theory, why does pressure increase as the temperature of an ideal gas increases? I. The gas molecules collide more frequently with the wall. II. The as molecules collide more energetically with the wall. (A) Only I (B) Only II (C) Both I and II (D) Neither I nor II

Which pure substance has the lowest vapor pressure at 25 °C? (A) CO2 (B) H2S (C) H2O (D) O2

The reaction is observed to have a Keq > 1. HSO3- (aq) + HPO4^2- (aq) --> SO3^2- (aq) + H2PO4- (aq) What is the strongest acid present in this equilibrium? (A) H2PO4^2- (B) HPO4^2- (C) HSO3^- (D) SO3^2-

If the half-life of a reaction is independent of concentration, the reaction can be I. first order II. second order III. zero order A) I and II only (B) II and Ill only (C) I only (D) II only

Which compound(s) exhibit(s) dipole-dipole forces? (A) I and II (B) III only (C) III and IV (D) II,III, IV

What is the Kc for this reaction? P4 (s) + 6Cl2 (g)~ 4PCI3 (g) (A) Kc = 1/[Cl2]^6 (B) Kc = [PCI3]^4 / [P4][Cl2]^6 (C) Kc = [PCI3]^4/ [Cl2]^6 (D) Kc = [P4][Cl2]^6/ [PCI3]^4

Xenon tetrafluoride, XeF4, can be prepared by heating Xe and F2 together: Xe(g) + 2F2 (g) --> XeF4 (g) What is the equilibrium constant expression for this reaction? (A) Kc = [XeF4]/[Xe][F2] (B) Kc= [XeF4]/[2Xe][F2] (C) Kc = [XeF4]/[Xe][F2]^2 (D) Kc = [Xe][F2]/ [XeF4]

The graph to the right represents four different gases at the same temperature. Which are the correct label for curves I-IV? Curve I Curve II Curve III Curve IV (A) CO2 F2 Cl2 Kr (B) Kr CO2 Cl2 F2 (C) Kr Cl2 CO2 F2 (D) F2 CO2 Cl2 Kr

(C) Kr Cl2 CO2 F2 speed (root mean squared speed) square root of 3RT/MolarMass the higher the molar mass the small the speed, lower molar mass = faster speed

The formation of a complex ion such as Cu(NH3)4^2+(aq) can best be categorized as a(n) _reaction. Cu^2+(aq) + 4NH3(aq)----> Cu(NH3)4^2+(aq) (A) Arrhenius acid-base (B) Bronsted-Lowry acid-base (C) Lewis acid-base (D) oxidation - reduction

Which ionic compound has the largest magnitude lattice energy? (A) CaO (B) KBr (C) MgO (D) NaF

What would be expected to be the most soluble in ethanol (CH3CH2OH)? (A) CH3CH2CH3 (B) CO2 (C) NH3 (D) SF6

What is the order of SeN, MgO, CaC]z, and NaBr in order of increasing magnitude of lattice energy? (A) CaCl2 < NaBr < SeN < MgO (B) CaCl2 < NaBr < MgO < SeN (C) NaBr < CaCl2 < MgO < SeN (D) NaBr < CaCl2 < SeN < MgO

Which molecule is polar? (A) CCl4 (B) CS2 (C) PH3 (D) PF5

Which statement regarding chemical reactions is true according to collision theory? (A) All molecular collisions result in chemical reactions. (B) Catalysts make individual collisions more effective, increasing reaction rates. (C) Proper orientation of molecules is required for collision to result in chemical reactions. (D) Increasing the temperature of a reaction decreases the kinetic energy of molecules, making collisions more effective.

Where is the hydrophilic (attracted to water) region of the molecules (A) Region I (B)Region 2 (C) Region 3 (D) The three regions are equally hydrophilic

Two vapor pressure curves, A and B are shown. One is for methanol, CH3OH, and the other is for 1-hexanol, CH3CH2CH2CH2CH2CH2OH. Which statement correctly completes the sentence? At T= 35C (A) curve A is 1-hexanol because 1-hexanol has weaker intermolecular forces than methanol. (B) curve A is I -hexanol because I -hexanol has stronger intermolecular forces than methanol. (C) curve A is methanol because methanol has weaker intermolecular forces than 1-hexanol. (D) curve A is methanol because methanol has stronger intermolecular forces than 1-hexanol.

(C) curve A is methanol because methanol has weaker intermolecular forces than 1-hexanol. Because both molecules have the same intermolecular forces, you would then consider the molar masses (or total number of electrons or size) of the molecules. The greater the molar mass, the stronger the intermolecular forces

Consider this reaction at equilibrium. 2SO2 (g)+ O2 (g)--> 2SO3 (g) deltaH = -198 kJ Which change would cause an increase in the SO3 /SO2 mole ratio? (A) adding a catalyst (B) removing O2(g) (C) decreasing the temperature (D) decreasing the pressure

Oxygen and ozone are allowed to come to equilibrium in the exothermic reaction 2O3 (g) --> 3O2 (g) Which change will increase the numerical value of the equilibrium constant, K? (A) adding more O2(g) (B) adding a suitable catalyst (C) decreasing the temperature (D) increasing the volume of the container

Under the same conditions of temperature and pressure, hydrogen (H2) diffuses __ than oxygen (O2). (A) two times slower (B) eight times slower (C) four times faster (D) sixteen times faster

For this chemical reaction at 25 °C, the concentration of the product is ____ the concentration of reactants at equilibrium, C2H4 (g) + H2(g) --> C2H6 (g) Kc = I.3x10^21 (A) less than (B) equal to (C) greater than (D) is not able to be compared to

For a gas sample containing equimolar amounts of nitrogen and hydrogen at 300 K, hydrogen has average ______ speed and ___average kinetic energy compared to nitrogen. (A) lower; the same (B) the same; the same (C) higher; the same (D) higher; higher

Which acid is the weakest in aqueous solution? (A) acetic acid (Ka = 1.8x 10-5) (B) formic acid (Ka = l.8x 10-4) (C) hydrocyanic acid (Ka = 6.2x 10-10) (D) nitrous acid (Ka = 4.5 x10-4)

The process described by changing the system from point A to point B is __ . (A) condensation (B) evaporation (C) melting (D) sublimation

What are the polarities of the indicated molecules? XeF2 XeF4 (A) polar nonpolar (B) polar polar (C) nonpolar nonpolar (D) nonpolar polar

Chemical equilibrium is the result of (A) a stoppage of further reaction. (B) the unavailability of one of the reactants. (C) opposing reactions attaining equal speeds. (D) formation of products equal in mass to the mass of the reactants

Consider the reaction 2NO2(g) + F2(g) --> 2NO2F(g) A proposed mechanism for the reaction is NO2 + F2 --> NO2F + F (slow) NO2 + F~--> NO2F (fast) What is the rate law for this mechanism? (A) rate = k ([NO2F]/ [NO2]^2 [F2]) (B) rate = k[NO2]^2 [F2] (C) rate = k[NO2][F2] (D) rate = k[NO2][F]

For the reaction of chorine and nitric oxide, 2NO(g) + Cl2(g) ----> 2NOCI(g) doubling the concentration of chlorine doubles the rate of reaction. Doubling the concentration of both reactants increases the rate of reaction by a factor of eight. The reaction is (A) first order in both NO and Cl2. (B) first order on NO and second order in Cl2. (C) second order in NO and first order in Cl2. (D) second order in both NO and Cb.

An 0=0 bond is than an 0-0 bond. (A) longer and stronger (B) longer and weaker (C) shorter and stronger (D)shorter and weaker

The table to the right gives the relative concentration of reactants and products at equilibrium for the generic reaction at two temperatures. The equilibrium constant is X + Z --->. XZ 300 K 0.7 0.3 0.8 500 K 1.0. 0.6. 0.5 (A) negative at 500 K. (B) larger at 500 K than at 300 K. (C) smaller at 500 K than at 300 K. (D) the same at 500 K and at 300 K.

What is the hybridization of the two labeled carbon atoms? C1. C2 (A) sp sp3 (B) sp2 sp (C) sp3 sp (D) sp3 sp3

The value of an equilibrium constant can be used to predict each of these except the (A) extent of a reaction. (B) direction of a reaction, (C) time required to reach equilibrium. (D) quantity of reactant(s) remaining at equilibrium.

What is the formal charge on the phosphorous atom in the phosphate ion as shown? (A) -3 (B) -1 (C) 0 (D) +5

(D) +5

A 0.152-mol sample of CH202 reacted completely according to the reaction shown, and 38.7 kJ of heat was released. What is delta H for this reaction? 2CH202 + 02 --+ 2C02 + 2H20 (A) 509 kJmol-1 (B) 254 kJ·moi-1 (C) -254 kJ·moi-1 (D) -509 kJ·moi-1

(D) -509 kJ·moi-1

What is the value of delta H of formation for this reaction? H2(g) + 1/2 O2(g) --> H2O(l) delta H formation 1 = -286 kJ·mol-1 3O2(g) --> 2O3 (g) delta H formation2 = 271 kJ·mol-1 3H2(g) + 03(g)----> 3H20(1) (A) -15 kJ/mol (B) -558 kJ/mol (C) -722 kJ/mol (D) -994 kJ/mol

(D) -994 kJ/mol

A mixture of 2.0 mol of CO(g) and 2.0 mol of H2O(g) was allowed to come to equilibrium in a 10.0-L flask at a high temperature. If Kc = 4.0, what is the molar concentration of H2(g) in the equilibrium mixture? CO(g) + H2O(g) --> CO2 (g) + H2 (g) (A) 0.67 M (B) 0.40 M (C) 0.20 M (D) 0.13 M

(D) 0.13 M

The mass percent of acetic acid (CH3COOH) in a bottle of vinegar is 5.45% in water. What is the molar concentration of acetic acid in vinegar, assuming the density of vinegar is 1.005 g/mL? Molar Mass CH3COOH 60.06 g/mol (A) 0.545 M (B) 0.903 M (C) 0.908 M (D) 0.912 M

(D) 0.912 M

The molecular orbital for He2^2+ and He2 are shown here. What are the bond orders of He2 ^2+ and He2? He2 ^2+ He2 (A) 2 4 (B) 2 (C) 2 0 (D) 1 0

(D) 1 0

What is the equilibrium concentration of nitrous acid, HNO2 (Ka = 4.5x 10-4), in a solution that has a pH of 1.65? (A) 0.0032 M (B) 0.022 M (C) 0.49 M (D) 1.1 M

(D) 1.1 M

Given the equilibrium constants for these reactions: 2CH4 (g) --> C2H6 (g) + H2(g) Kc = 9.5x10^-13 CH4 (g) + H2O(g) --> CH3OH(g) + H2 (g) Kc = 2.8x10^-21 What is the value of Kc for this reaction? 2CH3OH(g) + H2(g) --> C2H6 (g) + 2H2O(g) (A) 9.5x 10^-13 (B) 2.9x 10^-9 (C) 3.4 x 10 ^ 8 (D) 1.2 x 10 ^ 29

(D) 1.2 x 10 ^ 29 Kc1/(kc2)^2

What is Kb of F-? (Ka of HF is 6.8x10-4) (A) 6.8x10^10 (B) 1.5x10^3 (C) 6.8 X 10^-4 (D) 1.5 x10^-11

(D) 1.5 x10^-11 1.0 e -14 / 6.8 e -4

The pOH of pure water at 40C is 6.8. What is the hydronium concentration, [H30+], in pure water at this temperature (A) 1.0x 10 ^-14 M (B) 6.3x10 ^-8 M (C) 1.0x10^-7 M (D) 1.6x10^-7 M

(D) 1.6x10^-7 M pure water is usually neutral at 7, so just do 10^ -6.8 because its the new neutral

A certain reaction has deltaH =- 75 kJ ·mol-1 and an activation energy of 40 kJ ·mol-1. A catalyst is found that lowers the activation energy of the forward reaction by 15 kJ ·mol-1• What is the activation energy of the reverse reaction in the presence of the same catalyst? (A) 25 kJ ·mol-1 (B) 60 kJ ·mol-1 (C) 90 kJ ·mol-1 (D) 100 kJ·mol-1

(D) 100 kJ·mol-1

How many sigma and pi bonds are shown? (A) 3 sigma and 12 pi (B) 6 sigma and 9 pi (C) 9 sigma and 6 pi (D) 12 sigma and 3 pi

(D) 12 sigma and 3 pi

What is the pH of a 0.0050 M solution of Ba(OH)2 (aq) at 25 °C? (A) 2.00 (B) 2.30 (C) 11.70 (D) 12.00

(D) 12.00 pOH = -log (.01) 14-pOH = pH

At equilibrium in a 10 L vessel, there are 7.60x 10-2 moles of SO2, 8.60x 10-2 moles of O2, and 8.20x 10 -2 moles of SO3. What is the equilibrium constant Kc under these conditions? 2SO2 (g) + O2 (g) --> 2SO3 (g) (A) 12.5 (B) 13.5 (C) 125 (D) 135

(D) 135

A 1400 g sample of stream water contains 12.2 ppm of mercury. What is the mass of Hg in the sample? (A) 0.1 I mg (B) 2.4 mg (C) 8.7 mg (D) 17 mg

(D) 17 mg

How many sigma and pi bonds are in the molecule shown? (A) 5 sigma and 6 pi (B) 13 sigma and 5 pi (C) 16 sigma and 6 pi (D) 21 sigma and 6 pi

(D) 21 sigma and 6 pi

Which line segment represents the activation energy for the reaction between C and D to form A and B? (A) 1, 2, & 3 (B) 2 (C) 2 & 3 (D) 3

(D) 3

For the reaction, A(g) --> B(g) + C(g), 5 moles of A are allowed to come to equilibrium in a closed rigid container. At equilibrium, how much of A and B are present if 2 moles of C are formed? (A) 0 moles of A and 3 moles of B (B) l mole of A and 2 moles of B (C) 2 moles of A and 2 moles of B (D) 3 moles of A and 2 moles of B

(D) 3 moles of A and 2 moles of B

Which arrow on the phase diagram corresponds to the particle-level phase change shown? (A) 1 (B) 2 (C) 3 (D) 4

(D) 4 gas becoming solid

The gas phase reaction, A2 + B2 ---->2AB, proceeds by bimolecular collisions between A2 and B2 molecules. The rate law is rate =k[A2][B2] If the concentrations of both A2 and B2 are doubled, the reaction rate will change by a factor of (A) 1/2 (B) square root of 2. (C) 2. (D) 4.

(D) 4. 2A^2 = 4A

A solution of NaCl in water has a concentration of 20.5% by mass. What is the molal concentration of the solution? molar mass NaCl 58.44 g/mol (A) 0.205 m (B) 0.258 m (C) 3.51 m (D) 4.41 m

(D) 4.41 m

What volume of CO2(g), measured at 0.993 atm and 28 C, must react in order to completely consume 59.0 g of Al2O3(s)? Al2O3(s) + 3CO2 --> Al2(CO3)3(s) Molar mass Al2O3 = 101.96 g/mol (A) 1.34 L (B) 4.03 L (C) 14.4 L (D) 43.3 L

(D) 43.3 L

Carbon monoxide gas reacts with hydrogen gas at elevated temperatures to form methanol. CO(g) + 2H2 (g)--> CH3OH(g) When 0.40 mol of CO and 0.30 mol of H2 are allowed to reach equilibrium in a 1.0 L container, 0.060 mol of CH3OH are formed. What is the value of Kc? (A) 0.50 (B) 0.98 (C) 1.7 (D) 5.4

(D) 5.4

A mixture of 100 g of K2Cr2O7 and 200 g of water is stirred at 60 °C until no more of the salt dissolves. The resulting solution is poured off into a separate beaker, leaving the undissolved solid behind. The solution is now cooled to 20C. What mass of K2Cr2O7 crystallizes from the solution during the cooling? (A) 9 g (B) 18 g (C) 31 g (D) 62 g

(D) 62 g You see that: at 60 o C, the solubility is 40 g /100 g water so the 60 C solution above (once poured off) contained 80 g of K2Cr2O7 in 200 g of water. at 20 C, the solubility is 9 g/1 00 g water so the 20 C solution above (once cooled) contained 18 g of K2Cr2O7 in 200 g of water in solution. Meaning, the cooled solution had 80 g- 18 g or 62 g of K2Cr2O7 as a solid or crystallized from the water, which is choice (D).

What is the percent yield when 1.72 g of H2O2 decomposes and produces 375 mL of O2 gas measured at 42C and 1.52 atm? Molar mass H2O2 = 34.02 g/mol 2H2O2(aq)--> 2H2O(I) + O2(g) (A) 15.3% (B) 30.7% (C) 43.7% (D) 87.2%

(D) 87.2% 1.72 g H2O2 x 1 mol H2O2/ 34.02 g x 1 mol O2/2 mol H2O2 = 0.02579248 mol O2 PV=nRT = 0.022051228 mol O2 0.022051228 mol O2/0.02579248 mol O2 x 100

The rate constants for a specific reaction at two different temperatures are given in the table. What is the activation energy for the reaction? Temperature Rate constant 127 C 3 .0x 10-4 s-1 227 C 6.0x 10-2 s-1 (A) -88.1 kJ · mol-1 (B) -12.7 kJ-mol-1 (C) 12.7 kJ·mol-1 (D) 88.1 kJ ·mol-1

(D) 88.1 kJ ·mol-1

Which statement best describes ionic bonding in lithium fluoride? A) The positive and negative charges of the ions cancel out. (B) A lithium atom shares one electron with a fluorine atom. (c) An electron is transferred from a lithium atom to a fluorine atom. (D) An electrostatic attraction exists between lithium ions and fluoride ions.

(D) An electrostatic attraction exists between lithium ions and fluoride ions

Why is the boiling point of Br2 higher than that of Cl2? (A) Br2 has greater molar mass and is therefore easier to vaporize. (B) Br is less electronegative and therefore its bonding is more ionic. (C) Br is more electronegative and therefore has greater dipole-dipole forces. (D) Br2 is more polarizable and therefore has greater London dispersion forces.

(D) Br2 is more polarizable and therefore has greater London dispersion forces.

Which pair of compounds will form hydrogen bonds with one another? (A) CH4 and H2O (B) CH4 and NH3 (C) HF and CH4 (D) H2O and NH3

(D) H2O and NH3

Which aqueous acid has the largest Ka value? (A) HBrO (B) HBrO2 (C) HClO (D) HClO2

(D) HClO2

A technician has the measured osmotic pressure of a solution to determine the molar mass of a covalent solute. Which other information would need to be measured in order to determine the molar mass? I. Temperature II. Volume of solution Ill. mass of solute (A) Only I (B) Only III (C) Only I and II (D) I, II, III

(D) I, II, III

A catalyst is added to a system at equilibrium. Which statement is TRUE? (A) The temperature will decrease. (B) The equilibrium constant will increase. (C) The concentration of products will decrease. (D) If the system is disturbed, it will return to equilibrium faster.

(D) If the system is disturbed, it will return to equilibrium faster.

Activation energy can be experimentally determined from the slope of the plot of (A) k versus 1/T. (B) k versus InT. (C) Ink versus T. (D) Ink versus 1/T.

(D) Ink versus 1/T.

A student mixes 20.0 g of a salt in 100.0 g of water at 20C and obtains a homogeneous solution. Which salt could this be and why? Solubility at 20C in 100.0 g of water KCl 10.0 g KNO3 30.0g (A) KCI because it is saturated. (B) KCl because it is unsaturated. (C) KNO3 because it is saturated. (D) KNO3 because it is unsaturated.

(D) KNO3 because it is unsaturated. A homogeneous solution is one which is unsaturated. Solubility of KNO3 is 30g in the given conditions and added amount is only 20g so it is an unsaturated solution and hence is homogeneous.

What is the equilibrium expression for this reaction? 2C(s) + O2(g) --> 2CO(g) (A) Kc = [CO]/ [C][O2] (B) Kc = [CO]^2 / [C]^2[O2] (C) Kc = [2CO] / [2C][O2] (D) Kc = [CO]^2 / [O2]

(D) Kc = [CO]^2 / [O2]

The photosynthetic conversion of CO2 and O2 can be represented by the reaction shown. What is the equilibrium expression for this reaction? 6CO2 (g)+ 6H2O(l) --> C6H12O6 (s) + 6O2 (g) (A) Kc = [CO2]^6 [C6H12O6] / [O2]^6 [H2O]^6 (B) Kc = [CO2]^6 / [O2]^6 (C) Kc = [O2]^6 [H2O]^6 / [CO2]^6 [C6H12O6] (D) Kc = [O2]^6 / [CO2]^6

(D) Kc = [O2]^6 / [CO2]^6

When 100. g of an unknown compound was dissolved in 1.00 kg of water, the freezing point was lowered by 6.36 °C. What is the identity of this unknown compound? (Kf for water= l.86°C·m-1) (A) CsCI (B) KCI (C) LiF (D) NaCl

(D) NaCl

Which 0.10 M solution will have the largest concentration of hydroxide ion? (A) NH3 (Kb of NH3 = 2.8 x 10^ -5) (B) NaCN (Ka ofHCN = 4.9x10^-10) (C) NaClO2(Ka ofHClOz = 1.7x10^-4) (D) NaHCO3 (Kb ofHCO3-= 2.3x10^-8)

(D) NaHCO3 (Kb ofHCO3-= 2.3x10^-8)

For the reaction: 1/2F2 (g)--> F(g), a reaction mixture initially contains equal amounts of F2(g) and F(g) in their standard states. If Kp = 7.55 X 10^-2 at this temperature, which statement is true? (A) Q < K, and the reaction proceeds towards the reactants. (B) Q < K, and the reaction proceeds towards the products. (C) Q = K, and the reaction is at equilibrium. (D) Q > K, and the reaction proceeds towards the reactants

(D) Q > K, and the reaction proceeds towards the reactant

Which molecule has a 120° bond angle? (A) CO2 (B) NH3 (C) IF3 (D) SO3

(D) SO3

What is a proper description of chemical equilibrium? (A) The reaction has stopped. (B) The concentrations of products and reactants are equal. (C) The rates of the forward and reverse reactions are zero. (D) The rates of the forward and reverse reactions are the same.

(D) The rates of the forward and reverse reactions are the same.

This reaction reaches equilibrium in a closed container. What happens if the volume of the container is decreased at constant temperature? CH4 (g) + H2O(g) --> CO(g) + 2H2(g) (A) No change occurs. (C) The reaction shifts towards products. (B) The equilibrium constant increases. (D) The reaction shifts towards reactants.

(D) The reaction shifts towards reactants.

A pure substance is initially at 365 K and 545 torr. What happens to the substance when the pressure is increased to 760 torr at constant temperature? (A) The substance boils and become a gas. (B) The substance melts and becomes a liquid. (C) The substance sublimes and becomes a gas. (D) The substance condenses and becomes a liquid.

(D) The substance condenses and becomes a liquid.

According to VSEPR, what are the approximate values of the bond angles X and Y? (A) X is 90° and Y is 180° (B) X is 90° and Y is 120° (C) X is 109.5° and Y is 180° (D) X is 109.5° and Y is 120°

(D) X is 109.5° and Y is 120°

What intermolecular forces are present in a pure sample of ethanol (C2H5OH)? (A) dispersion and ion-dipole (B) dispersion and dipole-dipole (C) hydrogen bonding and ion-dipole (D) dispersion, dipole-dipole and hydrogen bonding

(D) dispersion, dipole-dipole and hydrogen bonding hydrogen bonding with the O and H polar all have dispersion

If the reaction O3(g) --+ O2(g) + O(g) is first order in 03, which plot will be linear? (A) [O3] VS. time (B) 1/[O3] vs. time (C) [O3]2 vs. time (D) ln[O3] vs. time

(D) ln[O3] vs. time

A gas behaves most ideally at (A) high pressures and low temperatures. (B) high pressures and high temperatures. (C) low pressures and low temperatures. (D) low pressures and high temperatures

(D) low pressures and high temperatures

Which factors will affect both the position of equilibrium and the value of the equilibrium constant for this reaction? N2 (g)+ 3H2 (g)--> 2NH3 (g) deltaH = -92 kJ (A) increasing the volume of the container (C) removed ammonia gas (B) adding more nitrogen gas (D) lowering the temperature

(D) lowering the temperature

Osmium(VIII) oxide, Os04, is a pale-yellow solid with a melting point of 40C and a boiling point of 130 °C. It is an electrical insulator. It is soluble in water, but the resulting solution is not conducting. Based on these observations what is the most appropriate classification ofOs04? (A) covalent-network solid (B) ionic solid (C) metallic solid (D) molecular solid

(D) molecular solid

What happens to the volume of a fixed amount of gas if both the pressure and absolute temperature are doubled? (A) halved (B) doubles (C) quadruples (D) no change

(D) no change V = nRT/P the 2 would cancel

The electronegativity of C is 2.5 and that of F is 4.0. What is the best description of a chemical bond between these two elements? (A) ionic bond (B) metallic bond (C) nonpolar covalent bond (D) polar covalent bond

(D) polar covalent bond

Plots are shown for the reaction NO2(g) ----> NO(g) + 1/2 O2(g). What is the rate law for the reaction? (A) rate = k (B) rate = k x (1 / [NO2]) (C) rate = k[NO2] (D) rate = k[NO2] 2

(D) rate = k[NO2] 2 Each of the integrated rate laws has the form of a y = mx + b equation. When you examine the plots provided, you notice that the plot of 1/[NO2] vs time is linear and the others are nonlinear. You decide that this means the rate law is a second order rate law

Which reaction rate is more affected by a change in temperature? Reaction Ea/ kJ/mol I H2(g) + h(g) ~ 2HI(g) 173 II CH3CHO(g) ~ CH4(g) + CO(g) 356 (A)reaction I because the activation energy is lower (B)reaction I because the number of moles of gas stays the same (C)reaction II because number of moles of gases increases as reaction goes forward (D) reaction II because the activation energy is higher

(D) reaction II because the activation energy is higher

When the reversible reaction N2(g) + O2(g) --> 2NO(g) has reached a state of equilibrium, (A) no further reactions occurs. (B) the total moles of products must equal the remaining moles of reactant. (C) the addition of a catalyst will cause formation of more NO. (D) the concentration of each substance in the system will be constant.

(D) the concentration of each substance in the system will be constant.

What is the molecular geometry of C03^2-? (A) bent (B) T -shaped (C) trigonal bipyramidal (D) trigonal planar

(D) trigonal planar

What is the oxidation number of chlorine in NaClO2? a) -1 b) +1 c) +3 d) +5

What is the oxidation number of Mo in MoO4 2-

Use the enthalpies of formation, delta H of formation, in the table to determine delta H for this reaction 2C2H2 (g) + 5O2(g) --> 4CO2(g) +2H2O(g) C2H2 227 kJ/mol H2O -242 kJ/mol CO2 -393 kJ/mol a) -2510 kJ/mol b) -2282 kJ/mol c) -862 kJ/mol d) 2510 kJ/mol

-2510 kJ/mol

What is the energy change for a system that releases 100 kJ of heat to its surroundings and has 25 kJ of work done on it?

-75 kJ 100 released (-100 kJ) + 25 done to it = -75 kJ

Guaifenesin (C10H14O4) is a common over-the-counter expectorant. What mass (in g) of oxygen is in 200 mg dose of Guaifenesin? (Molar mass of C10H14O4 = 198.2 g mol)/

0.0646 g

What solution volume is needed to prepare a 0.110 M solution of MgSO4 using 10.3 grams of the compound? The molar mass of MgSO4 is 120.366 g mol

0.778 L

What mass (in g) of sodium ions, Na+, are there in 25 mL of 0.75 Na2SO3?

0.87 g

What is the molar concentration of a solution when 7.00 mL of a 3.25 M aqueous solution is diluted to 25.00 mL?

0.910 M

A sample of ethanol (C2H6O) contains 3.025 g hydrogen. How many moles of carbon are in the sample? (Molar mass of C2H6O = 46.07 g mol)

0.9980

Two isotopes of hypothetical element X exist with abundances 30.00% 100 X and 70.00% 101 X, what is the appropriate atomic mass of X (in atomic units, amu)?

100.7

A 10.000g sample of water contains 11.19% H by mass. What would the %H in a 20.000 g sample of water?

11.19%

What is the mass of 1.75 moles of Zn?

114 g

How many moles of hydrogen atoms are in six moles of Ca(OH)2?

What mass (g) of oxygen does 25.5 grams of aluminum carbonate, Al2(CO3)3, contain? (Molar mass of Al2(CO3)3 = 233.99 g mol)

15.7 g

The halogen are found in group

what is the atomic number for an ion that has a charge of +1 and contains 18 electrons?

Which ground state electron configuration is possible for an atom in the second period?

1s2 2s1

What is the maximum number of electrons that can occupy an orbital labeled d xy?

A single tablet of regular strength Tylenol contains 325 mg of acetaminophen (C8H9NO2). How many moles of acetaminophen are in a single tablet of Tylenol? (Molar mass of C8H9NO2 = 151.2 g mol).

2.15 x 10 ^ -3

What mass (in g) of magnesium nitrate, Mg(No3)2, are required to produce 250.0 mL of a 0.0750 M solution?

2.79 g

How many sodium ions are in 25.0 g of Na2CO3? (Molar mass of Na2CO3 = 105.99 g mol).

2.84 x 10 ^ 23 ions

A cop of coffee contains 95.0 mg of caffeine, C8H10N4O2. How many caffeine molecules are in one cup? (Molar mass of C8H10N4O2 = 194.2 g mol)

2.95 x 10 ^ 20 molecules

How many neutrons are in 37 17 Cl-?

How many protons (p+), neutrons (n), and electrons (e-) are present in 47 22 Ti 3+

22 protons, 25 neutrons, and 19 electrons

What volume of 0.200 M K2C2O4 is required to react completely with 30.0 mL of 0.100 M Fe(NO3)3? 2Fe(NO3)3 + 3K2C2O4 --> Fe2(C2O4)3 + KNO3

22.5 mL

What volume (in mL) of a 0.0557 M Sr(OH)2 solution is needed to neutralize 36.4 mL of a 0.0750 M HNO3 solution?

24.5 mL

What is the energy of a photon with a wavelength (lambda) of 656 nm?

3.03 x 10 ^ -19 J

3TC is a small molecule, antiretroviral medication (C8H11N3O3S). What mass (in grams) of nitrogen is in 7.43 x 10 ^ -4 moles of 3TC? (Molar mass of C8H11N3O3S = 229.26 g mol).

3.12 x 10 ^ -2 g

What is the final concentration when a 28.2 mL of an 11/8 M solution is diluted to 100.0 mL?

3.33 M

How many atoms are in 1.50 grams of Al?

3.35 x 10 ^22

When excited, a sodium atom emits a photon of frequency 5.090 x 10 -14 s ^ -1. What is the energy associated with this emission

3.37 x 10 ^ -19 J

What is the wavelength of a photon with an energy of 6.51 x 10 - 19 J?

305 nm

What is the mass percent of oxygen in K2CO3? (molar mass of K2CO3 = 138.2 g mol)

34.73%

An atom of strontium - 90, 90, 38 Sr contains

38 electrons, 38 protons, 52 neutrons

A sample of a compound of xenon and fluorine contains molecules of a single type: XeFn, where n is a whole number. If 9.03 x 10 ^20 of these XeFn molecules have a mass of 0.311g, what is the value of n?

An atom of Fe has two 4s electrons and sex 3d electrons. How many unpaired electrons would there be in a Fe2+ atom?

What is the molar mass of K3Fe(C2O4)3? a) 122.96 g mol b) 261.15 g mol c) 359.10 g mol d) 437.15 g mol

437.15 g mol

What mass of Cl2 (g) is needed to release 45.2 kJ of energy as heat during the reaction of carbon and chlorine gas? C(s) + 2Cl2 --> CCl4(l) enthalpy of reaction = -135.4 kJ Mol

47.3 g

What volume of 0.100 M HCl is needed to neutralize 25.0 mL of 0.100 M Ba(OH)2? 2HCl + Ba(OH)2 --> BaCl2 + 2H2O

50.0 mL

What is the percent by mass of oxygen in Ca(NO3)2?

58.5%

What is the valence electron configuration for the element in Period 5, Group 3A?

5s2 5p1

Lithium has two naturally occurring isotopes, 6 Li and 7 Li, with masses of 6.015 amu and 7.016 amu, respectively. What is the relative abundance of each isotope?

6 Li = 7.49% and 7 Li= 92.51%

25.0 grams of carbon dioxide contains _______ oxygen atoms. (Molar mass CO2= 44.0 g mol)

6.80 x 10 ^23

Chlorine occurs naturally as a mixture of two isotopes with atomic masses of 34.97 amu and 36.97 amu. What are the relative abundances of these isotopes?

76% and 24%

How many neutrons are in 14 6 C?

Bromine has two naturally occuring isotopes. The most abundant isotope is (50.69%) is 79 35 Br of mass 78.9183 amu. What is the other isotope?

81 35 Br

What is the mass percent of carbon in isooctane (C8H18), a common component of gasoline?

84.12%

Which pure substance has the lowest boiling points?

What sample has the largest mass? a) 1 mole of marshmallows b) 1 mole of Pb (lead) atoms c) 1 mole of CO2 (carbon dioxide) molecules d) All of these have the same mass

A mole of marshmallows

Which pair pf particles has the same number of electrons? a) F-, Mg2+ b) Ne, Ar c) Br-, Se d) Al3+, P3-

A) F-, Mg2+

What is the correct Lewis structure for PF3?

Which correctly shows a hydrogen bond between two molecules of methanol? The hydrogen bond is represented as a dashed line.

B hydrogen bonding specifically is due to the presence of N, O, or F bonded to hydrogen with a lone pair of electrons on theN, O, or F.

Which ion has the same number if electrons as an argon atom? A) Mg2+ B) Cl- C) Ne D) Na+

B) Cl-

Which energy diagram best matches the proposed mechanism for this exothermic reaction? E + S --> ES (fast) ES --> E +P (slow)

Which molecule is most soluble in water? A B C D

Which point corresponds to the normal boiling point of a substance?

C where the graph shift from liquid to gas

Which ion has twenty-six electrons? A) Cr2+ B) Fe2+ C) Ni2+ D) Cu2+

C) Ni2+

The best Lewis structure of N2H2 shows (A) a nitrogen-nitrogen triple bond. (B) a nitrogen-nitrogen single bond. (C) each nitrogen with one nonbonding electron pair. (D) each nitrogen with two nonbonding electron pairs

C) each nitrogen with one nonbonding electron pair.

What is the empirical formula of a compound of carbon, hydrogen, and oxygen that contains 51.56% carbon and 14.09% hydrogen by mass?

C4H13O2

A 3.41 x 10 ^ -6 gram samples is known to contain 4.67 x 10 ^ 16 molecules. What is the compound? a) CH4 b) CO2 c) H2O d) NH3

CO2

Which compound contains the largest percent by mass of oxygen? a) CO2 b) NO2 c) SO2 d) SiO2

CO2

What are the oxidizing agent and the reducing agent in this reaction? Cu(NO3)2 (aq) + 2V(NO3)2 (aq) --> Cu(s) + 2V(NO3)3 (aq) oxidizing agent reducing agent a) V(NO3)2 Cu(NO3)2 b) Cu(NO3)2. V(NO3)2 c) Cu V(No3)2 d) V(NO3)2 Cu

Cu(NO3)2 is the oxidizing agent and V(NO3)2 is the reducing agent

Which figure illustrates a pi (n) bond?

Which pair of compounds will form hydrogen bonds with one another?

In the energy level diagram, transition between energy levels are denoted by arrows. Which transition corresponds to the absorption of the shortest wavelength of light? a) E2 to E1 b) E2 to E3 c) E3 to E2 d) E1 to E3

D) E1 to E3 shortest wavelength = highest energy (longest arrow)

Ethinyl estradiol (EE) is widely used in oral contraceptive pills. Which arrow points to the shortest carbon-carbon bond in EE? A) C = CH B) C-CH C) C-CH3 D) C triple bonded to CH

D, triple bond

Equation 1: SO2(g) --> S9S) + O2(g) Equation 2: 2SO2 (g) + O2 (g) --> 2SO3 (g)

Delta H = -Delta H of reaction 1 + 1/2 Delta H of reaction 2

What is the delta H of formation for HF (g)? 2HF (g) --> H2 (g) + F2 (g)

Delta H formation = 1/2 (-delta H reaction)

When the species F-, Na+, and Ne are arranged in order of increasing energy for the removal of an electron, what is the correct order?

F- < Ne < Na+

The species F-, Mg2+, and Na+ all have the same number of electrons. Which is the predicted order when they are arranged in order of decreasing size (largest first).

F- > Na+ > Mg2+

If gallium, atomic number 21, combines with selenium, atomic 34, what is the most likely formula based on tour knowledge of the periodic nature of the elements? a) GaSe b) GaSe2 c) Ga2Se d) Ga2Se3

Ga2Se3

Which compound has the highest percent composition by mass of oxygen? a) CaCO3 b) CaSO3 c) Li2CO3 d) Li2SO3

Li2CO3

Which pair of elements is listed in order of decreasing first ionization energy? a) Na. Mg b) Mg, Al c) Al, Si d) Si,P

Mg, Al

A 4.08 gram sample of a compound of nitrogen and oxygen contains 3.02 grams of oxygen. What is the empirical formula?

N2O5

Which compound is a weak electrolyte when dissolved in water? a) HNO3 b) KOH c) NH3 d) NaNO3

NH3

Arrange the elements Li, Ne, Na and Ar in increasing order of first ionization energy

Na < Li < Ar < Ne

Which compound contains the greatest percentage of nitrogen? a) KNO3 b) KNO2 c) NaNO3 d) NaNO2

NaNO2

When 1.0 M aqueous solutions of KI, NaC2H3O2, and Pb(NO3)2 are mixed together, what precipitate forms?

PbI2

In the compound (Nh4)2S2O3, which element is present in the largest percent by mass?

c) 151 kJ/mol (-(-543 kJ/mol) - (-484 kJ/mol) - (-92) you multiple by negative one for -543 and -484 because the reactions are reversed

What is the standard enthalpy change for the reaction? 2NH3(g) ----* N2H4(l) + H2(g) a) -935 kJ/mol b) 33 kJ/mol c) 151 kJ/mol d) 935 kJ/mol

The first three ionization energies of an element X are 590, 1145, and 4912 kJ mol ^ -1. What is the most likely formula for the stable ion of X? a) X+ b) X2+ c) X3+ d) X-

X2+

What mass of benzene, C6H6(L), must be burned in a bomb calorimeter to raise its temperature by 15 C? delta H combustion -41.9 kJ calorimeter constant 1.259 kJ C a) 0.45 g b) 2.2 g c) 19 g d) 500 g

a) 0.45 g -(1.259 kJ C)(15 C)/ (-41.9 kJ g)

When 68.00 J of energy are added to a sample of gallium that is initially at 25.0 °C, the temperature rises to 38.0 C. What is the volume of the sample? Data for Gallium, Ga specific heat 0.372 J·g-1·°C-1 density 5.904 g·cm-3 a) 2.38 cm^3 b) 4.28 cm^3 c) 14.1 cm^3 d) 31.0 cm^3

a) 2.38 cm^3

A solution is made by dissolving 60 g of NaOH (molar mass = 40 g mol) in enough distilled water to make 300 mL of a stock solution. What volumes of this solution and distilled water, when mixed, will result in a solution that is approximately 1 M NaOH? mL stock solution mL distilled water a) 20. 80 b) 20. 100 c) 60. 30 d) 60. 90

a) 20 mL stock solution and 80 mL distilled water

What is the molar concentration of the chloride ion in a 3.0 M CaCl2 solution? a) 6.0 M b) 3.0 M c) 1.5 M d) 1.0 M

a) 6.0 M

The number of atoms in 9.0 grams of aluminum is the same as the number of atoms in a) 8.1 g Mg b) 9.0 g Mg c) 12.1 g Mg d) 18.0 g Mg

a) 8.1 g Mg

For this reaction, what are the oxidizing and reducing agents? 2AuCl3 (aq) + 3H2 (g) --> 2Au(s0 + HCl (aq) a) AuCl3 is the oxidizing agent, H2 is the reducing agent b) H2 is the oxidizing agent, AuCl3 is the reducing agent c) Au is the oxidizing agent, HCl is the reducing agent d) HCl is the oxidizing agent, Au is the reducing agent

a) AuCl3 is the oxidizing agent, H2 is the reducing agent

Which combination is correct for the reaction represented by this equation? Cu(s) + Zn 2+(aq) --> Zn + Cu 2+ a) Cu is oxidized, Zn 2+ reduced b) Cu2+ is oxidized, Zn is reduced c) Zn is oxidized, Cu2+ is reduced d) Zn2+ is oxidized, Cu is reduced

a) Cu is oxidized, Zn 2+ reduced

Which one of these species (is/are) paramagnetic? a) Fe2+ only b) Zn only c) Ti4+ and Fe2+ only d) Fe2+ and Zn only

a) Fe2+ only

Which reaction will result in a precipitate? a) FeCl2(aq) + Na2S(aq) --> b) H2SO4 (aq) + NaOH (aq) --> c) KCl (aq) + CaBr2 (aq) --> d) Zn(NO3)2 (aq) + HI (aq) -->

a) FeCl2(aq) + Na2S(aq) --> precipitate is FeS

Which element is an alkali metal? a)K b) Mg c) V d) Fe

a) K

Which pair correctly shows the size difference between the species? a) Li+ > Be2+ b) Li+ > Na+ c) Li+ > Li d) S > S2-

a) Li+ > Be2+

Two metal samples, of the same mass and initially at 25.0 degrees C, are heated so that each metal receives the same amount of thermal energy. Which metal will have the highest final temperature? x 0.350 J/g x K z. 0.895 J/g x K a) X b) Z c) both will have the same final temperature d) it cannot be determined

a) X lowest specific heat so changes the most

Which of these elements has the smallest atomic radius? a) fluorine b) chlorine c) bromine d) iodine

a) fluorine

Which set of quantum numbers is correct and consistent with n=4? a) l=3, ml= -3, ms= 1/2 b) l=4, ml= +2, ms= -1/2 c) l=2, ml= +3, ms +1/2 d) l=3, ml= -3, ms = +1

a) l=3, ml= -3, ms= +1/2

The standard enthalpy change for the formation of silver chloride from its elements is __ than the enthalpy change for the formation of silver bromide. delta H formation / kJ x mol-1 AgCl(s) -127.1 AgBr(s) -100.4 a) more exothermic b) less exothermic c) more endothermic d) less endothermic

a) more exothermic more negative

Which electronic transition in a hydrogen atom is associated with the largest emission of energy? a) n=2 to n=1 b) n=2 to n=3 c) n=2 to n=4 d) n=3 to n=2

a) n=2 to n=1

Which emission line in the hydrogen spectrum occurs at the highest frequency? a) n=3 to n=1 b) n=4 to n=2 c) n=7 to n=5 d) n=10 to n=8

a) n=3 to n=1

Avogadro's number equals the number of

atoms in one mole of atoms and marbles in one mole of marbles

What is the oxidation number of chromium in Na2Cr2O7? a) +12 b) +6 c) +3 d) -2

b) +6

If a system's internal energy increases by 250 kJ after the addition of 375 kJ of energy as heat, what was the value of work in the process? a) -625 kJ b) -125 kJ c) 125 kJ d) 625 kJ

b) -125 kJ

Given this thermochemical data, what is the Delta H rxn for CO(g) + 1/2O2(g) --> CO2 C(s) + O2(g) --> CO2 delta H = -394 kJ mol 2C (s) + O2 (g) --> 2CO (g) delta H = -221 kj mol a) -615 kJ mol b) -284 kJ mol c) -173 kJ mol d) 173 kJ mol

b) -284 kJ mol

What is the molar concentration of a solution made by dissolving 8.56 g of sodium acetate in water and diluting to 750.0 mL? The molar mass of NaC2H3O2 is 82.03 g mol a) 5.30 M b) 0.139 M c) 0.104 M d) 0.0783 M

b) 0.139 M

A 10.0 gram sample of silver is heated to 100.0 C and then added to 20.0 g of water at 23.0 C in an insulated calorimeter. At thermal equilibrium, the temperature of the system was measured as 25.0 C. What is the specific heat of silver? (specific heat of water is 4.184) a) 0.053 J g C b) 0.22 J g C c) 4.5 J g C d) 8.4 J g C

b) 0.22 J g C

Which electron configuration is impossible? a) 1s2 2s2 2sp6 3s2 3p6 4s2 4d5 b) 1s2 2s2 2p6 2d2 c) 1s2 2s2 2p6 3s2 3p6 d) 1s2 2s2 2p5 3s1

b) 1s2 2s2 2p6 2d2

Iron can be converted to Fe20 3 according to the reaction below. How much heat (in kJ) is required to convert 10.5 g of iron to Fe203? 2Fe(s) + 3CO(g)--+ Fe20.1(s) + 3C02(g) deltaH = 26.8 kJ-mol-1 a) 1.76 kJ b) 2.53 kJ c) 5.04 kJ d) 13.4 kJ

b) 2.53 kJ

What is an example of an oxidation-reduction reaction? a) CaCO3 (s) --> CaO (s) + CO2 b) 2H2O2 (aq) --> O2(g) + 2H2O(l) c) NaHCO3 (s) + HCl (aq) --> NaCl (aq) + CO2(g) + H2O (l)

b) 2H2O2 (aq) --> O2(g) + 2H2O(l)

What mass of carbon is present on 0.500 mol of sucrose (C12H22O11)?

b) 72.0 g

A molecular compound is found to consist of 30.4% nitrogen and 69.6% oxygen. If the molecule contains 2 atoms of nitrogen, what is the molar mass of the molecule? a) 46 g mol b) 92 g mol c) 154 g mol d) 168 g mol

b) 92 g mol

What is the formula for the compound formed when an aluminum ion, Al3+, combines with an oxide ion O2- a) AlO b) Al2O3 c) Al3O2 d) AlO2

b) Al2O3

Which compound contains a +1 ion? a) MgO b) KCl c) NO d) AlP

b) KCl

What is the empirical formula for a compound that is comprised of 54.0% sodium, 8.50% boron, and 37.5% oxygen by mass? a) Na2B2O3 b) Na3BO3 c) Na3B2O2 d) Na4BO4

b) Na3BO3

Which combination will result in a precipitate forming? a) NaOH (aq) and HCl (aq) b) NaOH (aq) and FeCl3 (aq) c) NaNO3 (aq) and FeCl3 (aq) d) Zn(s) and HCl (aq)

b) NaOH (aq) and FeCl3 (aq)

Which of these atoms will be the smallest? a) Si (Z=14) b) P (Z=15) c) Ge (Z=32) d) As (Z=33)

b) P (z=15)

Which compound contains a group 14 metal? a) CCl4 b) SnCl2 c) GeF4 d) ZnCl2

b) SnCl2

Which element is an actinide? a) Rb b) U c) Mo d) Ga

b) U

What is the ground state electron configuration for the Zr2+ ion? A) [Kr] 5s2 B) [kr] 4d2 C) [Kr] 5s2 4d2 D) [Kr] 5s2 4d4

b) [Kr] 4d2

Which statement is true? a) the nucleus of an atom contains neutrons and electrons b) the atomic number of an element is the number of protons in one atom c) the mass number of the atom is the number of protons in the nucleus plus the number of electrons outside d) the number if electrons outside the nucleus is the same as the number of neutrons in the nucleus

b) the atomic number of an element is the number of protons in the one atom

When a cold block of aluminum at 0C is placed in room temperature water at 21C in an insulated cup, the water and the aluminum end up at a final temperature of 19C. Assuming there was no heat loss to the surroundings, which statement best describes the energy exchanged in this process? a) the block of aluminum lost the energy the water gained b) the block of aluminum gained the energy that the water lost c) the block of aluminum gained less energy compared to the energy lost by the water d) the block of aluminum gained more energy compared to the energy lost by the water

b) the block of aluminum gained the energy that the water lost

The molar enthalpy of formation for H20(I) is -285.8 kJ · mol-1. Which expression describes the enthalpy change for the reaction: 2H2O(l)--+ 2H2(g) + 02(g) delta h formation = ? a) -1/2(delta H formation) b) - (delta H formation) c) -2( delta H formation) d) 1/(delta H formation)

c) -2( delta H formation)

What is the concentration of the bromide ion if 25.0 mL og a 0.50 M AlBr3 solution combines with 40.0 mL of a 0.35 M NaBr solution? Assume volumes are additive a) 7.9 x 10 ^ -4 mol L b) 0.41 mol L c) 0.79 mol L d) 2.1 mol L

c) 0.79 mol L

A 1.00 g sample of glucose, C6H1206, is burned in a bomb calorimeter, the temperature of the calorimeter rises by 9.40C. What is the heat capacity of the calorimeter? Table of Data C6H 1206(s) 180.2 g/mol Delta Hcombustion -2.83 x 10^3 kJ /mol a) -301 kJ/C b) -1.67 kJ/C c) 1.67 kJ/C d) 301 kJ/C

c) 1.67 kJ/C 1.00 g x 1 mol/ 180.2 g = 0.00554939 mol 0.00554939 mol x -2.83 x 10^3 kJ /mol = -15.70477248 kJ -15.70477248 kJ / -9.40 (because reaction = -qcalorimeter)

A 10 gram sample of which substance contains the greatest number of hydrogen atoms? a) 10 grams CH4 b) 10 grams HCl c) 10 grams H2 c) 10 grams PH3

c) 10 grams H2

What mass of carbon is present in 1.4 x10 ^20 molecules of sucrose (C12H22O11)? (Molar mass of C12H22O11= 342 g mol). a) 2.0 x 10 ^22 g b) 1.7 x 10 ^ 21 g c) 3.3 x 10 ^ -2 g d) 2.8 x 10 ^ -3 g

c) 3.3 x 10 ^ -2 g

If 345 kJ of energy is transferred to a system as heat while the system does 42 kJ of work, what will be the change in internal energy of the system after the processes are complete? a) -303 kJ b) -387 kJ c) 303 kJ d) 387 kJ

c) 303 kJ

A piece of iron is heated to 95.0 °C and then placed in an insulated vessel containing 250. g of water at 25.0 °C. When the system comes to equilibrium the temperature of the system is 35.0 °C. What is the mass (in g) of the iron? Assume no heat is lost to the surroundings. Specific heat I J ·g-1. K-1 Iron 0.450 water 4.184 a) 4.48 g b) 41.7 g c) 387 g d) 612 g

c) 387 g

Which type of electron is described by the quantum numbers n=3, l= 2, ml = 1 and ms= 1/2? a) 2p b) 3p c) 3d d) 3f

c) 3d

What is the wavelength of light (in nm) produced by the electronic transition between levels 4 and 2 of a hydrogen atom? a) 182 nm b) 364 nm c) 486 nm d) 1450 nm

c) 486 nm

THC, the active agent in marijuana, contains 80.16% carbon, 9.63% hydrogen, and 10.17% oxygen by mass. What is the empirical formula of THC? a) C7H10O b) C8HO c) C21H30O2 d) C30H3O5

c) C21H30O2

What is/are the spectator ion(s) in this reaction? HC2H3O2 (aq) + NaOH(aq) --> NaC2H3O2 (aq) + H2O a) C2H3O2- only b) H+ and OH- c) Na+ only d) Na+ and C2H3O2-

c) Na+ only

Which atom has the largest atomic radius? a) K b) I c) Rb d) Sn

c) Rb

Which compound below contains a transition metal? a) NaF b) AlCl3 c) VO2 d) BF3

c) VO2

One gram samples of carbon and copper, originally at room temperature, reach equilibrium after being placed on 200 mL of boiling water? (specific heat of carbon 0.709, specific heat of cooper 0.385) Which statement is correct?

copper would absorb less energy than carbon and attain the same final temperature as carbon

What is the ground-state electron configuration of the manganeses atom, Mn? a) 1s2 2s2 2p6 3s2 3p6 4s2 4d5 b) 1s2 2s2 2p6 3s2 3p6 3d7 c) 1s2 2s2 2p6 3s2 3p6 4s2 4p5 d) 1s2 2s2 2p6 3s2 3p6 3d5 4s2

d) 1s2 2s2 2p6 3s2 3p6 3d5 4s2

A single molecule of a certain compound has a mass of 3.4 x 10 ^ -22 g. Which value comes closest to the mass of a mole of this compound? a) 50 g mol b) 100 g mol c) 150 g mol d) 200 g mol

d) 200 g mol

What is the electron configuration of the valence electrons for a ground-state Ge atom? a) 4p2 b) 4s2 3d10 4p2 c) 3d10 4p2 d) 4s2 4p2

d) 4s2 4p2

In which reaction is carbon reduced? a) CO (g) + O2 (g) --> CO2 (g) b) CO2(g) + H2O (l) --> H2CO3 (aq) c) CH4 (g) + 2O2 (g) --> CO2 (g) + 2H2O (l) d) C2H2(g) + H2 (g) --> C2H4 (g)

d) C2H2(g) + H2 (g) --> C2H4 (g)

Which equation corresponds to the electron affinity of chlorine? a) Cl-(g) --> Cl(g) + e- b) Cl2 + e- --> Cl2- c) Cl(g) --> Cl+ + e- d) Cl(g) + e- --> Cl-

d) Cl(g) + e- --> Cl-

Which is an example of an oxidation-reduction reaction? a) HCl (aq) + RbOH(aq) --> H2O(l) + RbCl(aq) b) (NH4)2CO3(s) --> 2NH3 (g) + CO2 (g) + H2O (g) c) Pb(NO3)2 (aq) + Na2SO4(aq) --> PbSO4(s) + 2NaNO3 (aq) d) Pb(s) + PbO2(s) + 2H2SO4 (aq) --> PbSO4(s) + 2H2O (l)

d) Pb(s) + PbO2(s) + 2H2SO4 (aq) --> PbSO4(s) + 2H2O (l)

Magnesium forms an ionic compound with an element with the formula MgX. Which ion could be X? a) Br- b) P3- c) C4- d) S2-

d) S2-

In which compound does vanadium have the lowest oxidation state? a) V2O5 b) V2O3 c) VO2 d) VO

d) VO

Which species has this ground-state electron arrangement? 1s2 2s2 2p6 3s2 3p6 3d10 a) Ni b) Ni2+ c) Zn d) Zn2+

d) Zn2+

A student mixes I00 mL of 0.50 M NaOH with 100 mL of 0.50 M HCI in a Styrofoam cup and observes a temperature increase of deltaT1. When she repeats the experiment using 200 mL of each solution. she observes a temperature change of deltaT2. If no heat is lost to the surroundings or absorbed by the Styrofoam cup, what is the relationship between deltaT1 and deltaT2? a) delta T2= 4DeltaT1 b) delta T2= 2 Delta T1 c) delta T2= 0.5 Delta T1 d) delta T2 = delta T1

d) delta T2 = delta T1

Which statement below is correct? a) Chlorine is a transition metal b) Oxygen is a metal c) Sodium is a metalloid d) Phosphorous is a nonmetal

d) phosphorous is a nonmetal

Which atom has the most neutrons? a) neon-20 b) phosphorous-32 c) chlorine-35 d)sulfur - 35

d) sulfur-35

What particles would be present in NH3 (aq)? a) water molecules, NH4+ ions and OH- ions b) water molecules, H3O+ ions and NH2- ions c) water molecules and NH3 molecules d) water molecules and NH3 molecules and a small number of NH4+ ions and OH- ions

d) water molecules and NH3 molecules and a small number of NH4+ ions and OH- ions

Which term best describes the relation of hydrogen and deuterium (2H)?

isotopes

Which element is more electronegative than arsenic and less electronegative then sulfur? a) chlorine b) phosphorous c) tin d) oxygen

phosphorous

The radii of the ions in this series decrease because Ion. Ionic radius Na+. 0.095 nm Mg2+. 0.065 nm Al3+ 0.050 nm

the effective nuclear charge is increasing

A pair of isotopes has

the same number of protons and a different number of neutrons

As water is being added a concentrated NaOH solution

the volume of the solution is increasing, and the molarity is decreasing

What is the best procedure to prepare 0.500 L of a 0.200 M solution of Li3PO4? The molar mass of Li3PO4 is 115.8 g mol?

weigh 11.6 g solute and add suffucient water to obtain a final volume of 0.500 L.

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