2
68Assign a formal charge to the phosphorus atom (P) in the phosphate ion,
+1
9 What is the charge formed by alkaline earth metals when they react with nonmetals?
+2
44. Using the following bond energies Bond Bond Energy (kJ/mol) CºC 839 C-H 413 O=O 495 C=O 799 O-H 467 estimate the heat of combustion for one mole of acetylene: C2H2(g) + (5/2)O2(g) ® 2CO2(g) + H2O(g)
-1228 kj/mol
Which is the freezing point of a 2.00 m aqueous solution of sucrose? The value of Kf for water is 1.86 degrees c/molal. a. -3.72 degrees C b. -1.86 degrees C c. +1.86 degrees C d. +3.72 degrees C
-3.72 degrees C
28 Which of the following is the correct Lewis dot formula for H2S?
...
69One of two resonance structures for benzene, C6H6, an industrial solvent, can be written as:
....
For the equilibrium 2SO3 <--->2SO2+O2, kc is 4.08x10^-3 at 1000K A. 3.35 B.335
.335
The half- life of a first order reaction is equal to ____. A. .693/k B. .693k C. k/2 D. 2k
.693/k
32Draw the Lewis dot formula for NH4+. How many unshared pairs of electrons are in the outer shell of the central nitrogen atom?
0
Atoms which are sp2 hybridized form ____ pi bond(s).
1
Which solution has the greatest buffer capacity a. 1 L of solution containing 0.1 NH3 and 0.1 M NH4Cl b. 1 L of solution containing 0.05 NH3 and 0.05 M NH4Cl b. 1 L of solution containing 0.1 NH3 and 0.01 M NH4Cl d. 1 L of solution containing 0.5 NH3 and 0.5 M NH4Cl
1 L of solution containing 0.5 NH3 and 0.5 M NH4Cl
A and B are two gases that are mixed together; 2.50 mol A is mixed with 0.85 mol B. If the final pressure of the mixture is 1.75 atm, what are the partial pressures of A and B? Suppose that 0.25 mole of gas C was added to the mixture without changing the total pressure of the mixture. How does the addition of C to the mixture change the mole fraction of gas A? How does the addition of C to the mixture change the partial pressure of gas A? What is the partial pressure of C?
1.31 atm A 0.44 atm B decreases it decreases it 0.12 atm C
The overall order of a chemical reaction represented in the following rate law is rate= k[CHCl3][Cl2] A. 2 B. 1 C. 1.5
1.5
A gas cylinder contains 2.0 mol of gas X and 6.0 mol of gas Y at a total pressure of 2.1 atm. What is the partial pressure of gas Y?
1.6 atm
What is the pH of a 0.0200 M aqueous solution of HBr a. 1.00 b. 1.70 c. 2.30 d. 12.30
1.70
HA <-> H+ + A- [HA] = 1.65e-2 M and [H+] = [A-] = 5.44e-4 at equilibrium Kc = ___________? a. 1.79e-2 b. 1.79e-3 c. 1.79e-4 d. 1.79e-5
1.79e-5
For BaF2, Ksp = 1.7e-6. If KF is added to a saturated solution so that [F1-] = 0.10 M, what is [Ba2+] a. 1.7e-6 M b. 1.7e-5 M c. 1.7e-4 M d. 1.7e-3 M
1.7e-4 M
What is the percentage by mass of HCl in a 0.500 M solution of HCl at room temperature? Dhcl, 25ºC = 1.00 g/mol a. 1.82% b. 50.0% c. 0.911% d. some other value
1.82%
The reaction A<--->2 B has an equilibrium constant of K=.010. What is the equilibrium constant for the reaction B<--->1/2 A A. 1 B. 10 C. 100
10
What is the pH of a 0.0400 M aqueous solution of KOH a. 12.60 b. 10.30 c. 4.00 d. 1.40
12.60
5. How many unpaired electrons are shown in a Lewis Dot Formula for silicon?
2
60How many resonance structures does the bicarbonate ion, HCO3-, have?
2
17 What is the charge on the simple (single atom) ion that sulfur forms?
2-
A first- order reaction has a rate constant of .33 s-1. The half life of this reaction is? A. .48 B. 2.1 C. .33
2.1
consider the reaction A2 + 3 B2 -> 3 AB3. if deltA is -0.750 M/min, the deltB is a. -0.750 M/min b. -0.225 M/min c. -0.250 M/min d. 2.25 M/min
2.25 M/min
Chemical process for the formation of NH3 from H2 and N2 has an equilibrium constant of 4.34x10^-3. The equilibrium constant for the reverse reaction will be--- A. 4.34 x10^-3 B. 2.3X10^2 C. 2.3X10^4
2.3X10^2
What is the pH of a 0.0200 M aqueous solution of HF? The Ka of HF is 6.8e-4. a. 1.70 b. 2.43 c. 3.17 d. 12.30
2.43
If t1/2=100 s for a first-ordered reaction, how long will it take for the concentration of a reactant to decrease to 1/4 of its original value? A. 50 s B. 290 s C. 200 s
200 s
If t1/2= 500 s for a first-order reaction, how long will it take for the concentration of a reactant to decrease to 1/16 of its original value? A. 1000 s B. 1500 s C. 2000 s
2000 s
27
27
11 Which Lewis dot notation for atoms and ions is correct for the reaction for the formation of aluminum oxide?
2Al + O -> 2Al3+ , 3[O]2-
33How many shared pairs of electrons are in the outer shell of the central nitrogen atom of NH3?
3
59How many resonance structures does the nitrate ion, NO3-, have?
3
81How many sigma bonds and how many pi bonds does the acetylene molecule contain?
3 sigma and 2 pi
The half- life of a reaction with the first order rate constant of .02 s^-1 is ___s. A. 3.5 B. 35 C. .35
3.5
10Which Lewis dot notation for atoms and ions is correct for the reaction for the formation of calcium phosphide?
3Ca: +2 P -> 3Ca2+ , 2[ P ]3-
67When to atoms form a double covalent bond, how many electrons do they share?
4 electrons, 2 electron pairs
34The total number of valence electrons that must be shown in the dot formula for the C4H5Cl2FO molecules is ______. (It is not necessary to draw the dot formula.)
48
3. how many valence electrons does a phosphorus atom have?
5
79How many sigma bonds and how many pi bonds does the ethene molecule contain?
5 sigma, 1 pi
Five gases combined in a gas cylinder have the following partial pressures: 3.00 atm (N2), 1.80 atm (O2), 0.29 atm (Ar), 0.18 atm (He), and 0.10 atm (H). What is the total pressure that is exerted by the gases?
5.37 atm
4. How many valence electrons does a bromine atom have?
7
15 Lithium and chlorine react to form LiCl, an ionic compound. The chlorine ion,Cl-, has _____ electrons in its outermost occupied shell?
8
16 Magnesium and nitrogen react to form Mg3N2 an ionic compound. The magnesium ion, Mg2+, has ____ electrons in its highest occupied energy level.
8
For HCN, Ka = 4.9e-10. What is the pH of a buffer solution in which [HCN] = 0.100 M = [KCN] ? a. 4.7 b. 7.0 c. 9.3 d. 14.0
9.3
2 NO(g) + O2(g) → 2 NO2(g) A possible mechanism for the overall reaction represented above is the following: (1) NO(g) + NO(g) → N2O2(g) slow (2) N2O2(g) + O2(g) → 2 NO2(g) fast Which of the following rate expressions agrees best with this possible mechanism? (A) Rate = k[NO]2 (D) Rate = k[NO]2[O2] (B) Rate = k[NO] (E) Rate = k[N2O2][O2] [O2] (C) Rate = k[NO]2 [O2]
A
26. According to the rate law for the reaction, an increase in the concentration of hydronium ion has what effect on this reaction? (A) The rate of reaction increases. (B) The rate of reaction decreases. (C) The value of the equilibrium constant increases. (D) The value of the equilibrium constant decreases. (E) Neither the rate nor the value of the equilibrium constant is changed.
A
H3AsO4 + 3I−+ 2 H3O+ H3AsO3 + I3− + H2O The oxidation of iodide ions by arsenic acid in acidic aqueous solution occurs according to the stoichiometry shown above. The experimental rate law of the reaction is: Rate = k [H3AsO4] [I−] [H3O+] 25. What is the order of the reaction with respect to I−? (A) 1 (B) 2 (C) 3 (D) 5 (E) 6
A
Time (days) 0 1 2 3 4 5 6 7 ... 10 ... 20 % Reactant Remaining 100 79 63 50 40 31 25 20 ... 10 ... 1 A reaction was observed for 20 days and the percentage of the reactant remaining after each day was recorded in the table above. Which of the following best describes the order and the half-life of the reaction? Reaction Order Half-life(days) (A) First 3 (B) First 10 (C) Second 3 (D) Second 6 (E) Second 10
A
Complete the table by filling in the missing information.
A - pressure, volume B - temperature, moles of gas C - Charles's law D - V = kT E - temperature, pressure F - P = kT G - number of moles only
Small value for K, large Ea
A long half life means slow reaction rate
reaction rate
A measure of how quickly or slowly reactants are consumed (used up) or products are formed in a chemical reaction
Temperature
A measure of the average kinetic energy (speed) of the particles
Ignored
A negative sign for a reaction rate is
Fast
A reaction that occurs in a short period of rule has a ___ reaction rate
Large value for K, small Ea
A short half life means a fast reaction
Catalysts
A substance that changes the tests of a chemical reaction without being permanently consumed its self (used in one step and regenerated in another)
activated complex
A theoretical high energy particle that exists for a fraction of a second at the instant the particles collide
Based on electronegativity differences, which of the following is most likely to be ionic? A) BaF2 B) Cl2 C) NH3 D) NO3 E) CH4
A) BaF2
Which of the following molecules has no dipole moment? A) CO2 B) NH3 C) H2O D) all E) none
A) CO2
In the gaseous phase, which of the following diatomic molecules would be the most polar? A) CsF B) CsCl C) NaCl D) NaF E) LiF
A) CsF
Which of the following arrangements is in order of increasing size? A) Ga3+ > Ca2+ > K+ > Cl- > S2- B) S2- > Cl- > K+ > Ca2+ > Ga3+ C) Ga3+ > S2- > Ca2+ > Cl- > K+ D) Ga3+ > Ca2+ > S2- > Cl- > K+ E) Ga3+ > Ca2+ > S2- > K+ > Cl-
A) Ga3+ > Ca2+ > K+ > Cl- > S2-
Consider the following: I. Al, Si, P, S II. Be, Mg, Ca, Sr III. I, Br, Cl, F IV. Na+, Mg2+, Al3+, Si4+ Which of these is an isoelectronic series? A) IV B) III C) II D) I E) none of them
A) IV
Choose the statement that best describes the PbCl4 molecule in the gas phase. A) The bond angles are all about 109°. B) The molecule is polar. C) The molecule has a dipole moment. D) The bonds are nonpolar. E) a, b, and c
A) The bond angles are all about 109°
Adding bromide ion to a saturated aqueous solution of ___________ decreases its solubility in water a. BaSO4 b. Li2CO3 c. PbS d. AgBr
AgBr
24 Which of the following formulas is incorrect?
Al3O2
23 Which one of the formulas below is incorrect?
Al3P2
19 What is the formula for the binary compound of aluminum and nitrogen?
AlN
27. In the presence of alcohol dehydrogenase, the rate of reduction of acetaldehyde to ethanol increases as the concentration of acetaldehyde is increased. Eventually, the rate of the reaction reaches a maximum, at which point further increases in the concentration of acetaldehyde have no effect. Why?
All the alcohol dehydrogenase molecules are bound to acetaldehyde molecules.
Rate of chemical reaction increases with temperature due to ___ A. A decrease in the collision frequency B. The depression in freezing point C. An increase in the collision frequency
An increase in the collision frequency
Increase
As concentration increases, the reaction rate will
53Which one of the following molecules violates the octet rule?
AsF5
88Which one of the following pairs of molecules and molecular geometries is incorrectly matched?
AsF5 pentagonal planar
1. which Lewis dot formula below is incorrect
B
36. The initial-rate data in the table above were obtained for the reaction represented below. What is the experimental rate law for the reaction? (A) rate = k[NO] [O2] (B) rate = k[NO] [O2]2 (C) rate = k[NO]2 [O2] (D) rate = k[NO]2 [O2]2 (E) rate = k[NO] / [O2]
B
49. The isomerization of cyclopropane to propylene is a first-order process with a half-life of 19 minutes at 500 °C. The time it takes for the partial pressure of cyclopropane to decrease from 1.0 atmosphere to 0.125 atmospheres at 500 °C is closest to... (A) 38 minutes (B) 57 minutes (C) 76 minutes (D) 152 minutes (E) 190 minutes
B
57. rate = k[X] For the reaction whose rate law is given above, a plot of which of the following is a straight line? (A) [X] versus time (B) ln [X] versus time (C) 1/(X) verses time (D) [X] versus 1/time (E) ln [X] versus 1/time
B
Step 1: Ce4+ + Mn2+ Ce3+ + Mn3+ Step 2: Ce4+ + Mn3+ Ce3+ + Mn4+ Step 3: Mn4+ + Tl+ Tl3+ + Mn2+ 23. The proposed steps for a catalyzed reaction between Ce4+ and Tl+ are represented above. The products of the overall catalyzed reaction are... (A) Ce4+ and Tl+ (B) Ce3+ and Tl3+ (C) Ce3+ and Mn3+ (D) Ce3+ and Mn4+ (E) Tl3+ and Mn2+
B
The graph to the right shows the results of a study of the reaction of X with a large excess of Y to yield Z. The concentrations of X and Y were measured over a period of time. According to the results, which of the following can be concluded about the rate of law for the reaction under the conditions studied? (A) It is zero order in [X] (B) It is first order in [X]. (C) It is second order in [X]. (D) It is the first order in [Y]. (E) The overall order of the reaction is 2.
B
Given the following information: Li(s) ® Li(g) heat of sublimation of Li(s) = 166 kJ/mol HCl(g) ® H(g) + Cl(g) bond energy of HCl = 427 kJ/mol Li(g) ® Li+(g) + e- ionization energy of Li(g) = 520. kJ/mol Cl(g) + e- ® Cl-(g) electron affinity of Cl(g) = -349 kJ/mol Li+(g) + Cl-(g) ® LiCl(s) lattice energy LiCl(s) = -829 kJ/mol H2(g) ® 2H(g) bond energy of H2 = 432 kJ/mol calculate the net change in energy for the reaction 2Li(s) + 2HCl(g) ® 2LiCl(s) + H2(g) A) 363 kJ B) -562 kJ C) -179 kJ D) -73 kJ E) None of these
B) -562 kJ
How many of the following molecules possess dipole moments? BH3, CH4, PCl5, H2O, HF, H2 A) 1 B) 2 C) 3 D) 4 E) 5
B) 2
Based on electronegativities, which of the following would you expect to be most ionic? A) N2 B) CaF2 C) CO2 D) CH4 E) CF4
B) CaF2
39. Choose the molecule with the strongest bond. A) F2 B) Cl2 C) Br2 D) I2
B) Cl2
For the elements Cs, F, and Cl, the order of increasing electronegativity is: A) F < Cl < Cs B) Cs < Cl < F C) Cl < Cs < F D) F < Cs < Cl E) None of these
B) Cs < Cl < F
Choose the compound with the most ionic bond. A) LiCl B) KF C) NaCl D) LiF E) KCl
B) KF
Which of the following pairs is isoelectronic? A) Li+ and K+ B) Na+ and Ne C) I- and Cl- D) S2- and Ne E) Al3+ and B3+
B) Na+ and Ne
For the elements Rb, F, and O, the order of increasing electronegativity is: A) Rb < F < O B) Rb < O < F C) O < F < Rb D) F < Rb < O E) None of these
B) Rb < O < F
The electron pair in a C-F bond could be considered A) closer to C because carbon has a larger radius and thus exerts greater control over the shared electron pair. B) closer to F because fluorine has a higher electronegativity than carbon. C) closer to C because carbon has a lower electronegativity than fluorine. D) an inadequate model since the bond is ionic. E) centrally located directly between the C and F.
B) closer to F because fluorine has a higher electronegativity than carbon.
Atoms with very similar electronegativity values are expected to form A) no bonds. B) covalent bonds. C) triple bonds. D) ionic bonds. E) none of these
B) covalent bonds
Metals typically have _______ electronegativity values. A) high B) low C) negative D) no E) two of these
B) low
As a chemical reaction proceeds, the reactant concentration tends to ____. A. Increase B. Decrease C. Remain constant D. Oscillate
B. Decrease
46Which one of the following dot formulas is incorrect?
BCl3
54Which one of the following violates the octet rule?
BCl3
50Which of the responses includes all of the following molecules that have no unshared pairs of electrons about the central atom, and no other molecules?
BCl3 and AsF5
55Which of the following compounds is a lewis acid?
BF3
66What is the chemical formula for beryllium sulfide?
BeS
Which element below has the highest boiling point a. Kr b. F2 c. Cl2 d.Br2
Br2
28. 2 A(g) + B(g) ⇄ 2 C(g) When the concentration of substance B in the reaction above is doubled, all other factors being held constant, it is found that the rate of the reaction remains unchanged. The most probable explanation for this observation is that... (A) the order of the reaction with respect to substance B is 1. (B) substance B is not involved in any of the steps in the mechanism of the reaction. (C) substance B is not involved in the rate-determining step of the mechanism, but is involved in subsequent steps. (D) substance B is probably a catalyst, and as such, its effect on the rate of the reaction does not depend on its concentration. (E) the reactant with the smallest coefficient in the balanced equation generally has little or no effect on the rate of the reaction.
C
58. (CH3)3CCl(aq) + OH− (CH3)3COH(aq) + Cl− For the reaction represented above, the experimental rate law is given as follows: Rate = k [(CH3)3CCl] If some solid sodium solid hydroxide is added to a solution that is 0.010-molar in (CH3)3CCl and 0.10-molar in NaOH, which of the following is true? (Assume the temperature and volume remain constant.) (A) Both the reaction rate and k increase. (B) Both the reaction rate and k decrease. (C) Both the reaction rate and k remain the same. (D) The reaction rate increases but K remains the same (E) The reaction rate decreases but k remains the same.
C
82. Nitramide, N2H2O2, decomposes slowly in aqueous solution. This decomposition is believed to occur according to the reaction mechanism above. The rate law for the decomposition of nitramide that is consistent with this mechanism is given by which of the following? (A) Rate = k [N2H2O2] (B) Rate = k [N2H2O2] [H+] (C) Rate = (k [N2H2O2]) / [H+] (D) Rate = (k [N2H2O2]) / [N2HO2−] (E) Rate = k [N2H2O2] [OH−]
C
Which of the following is a correct statement about reaction order? (A) Reaction order can only be a whole number (B) Reaction order can be determined only from the coefficients of the balanced equation for the reaction (C) Reaction order can be determined only by experiment (D) Reaction order increases with increasing temperature (E) A second-order reaction must involve at least two different compounds as reactants
C
Which of the following molecules is non-polar overall? A) SF4 B) SF2 C) CCl4 D) H2S E) OCl2
C) CCl4
As indicated by Lewis structures, which of the following would probably not exist as a stable molecule? A) CH3OH B) CH2O C) CH3O D) C2H2 E) C3H4
C) CH3O
Which of the following molecules has a dipole moment? A) BCl3 B) SiCl4 C) PCl3 D) Cl2 E) none of these
C) PCl3
Which of the following has a zero dipole moment? A) NH3 B) NO2 C) PF5 D) SO2 E) HCN
C) PF5
Which of the following statements concerning lattice energy is false? A) It is often defined as the energy released when an ionic solid forms from its ions. B) MgO has a larger lattice energy than NaF. C) The lattice energy for a solid with 2+ and 2- ions should be two times that for a solid with 1+ and 1- ions. D) MgO has a larger lattice energy than LiF. E) All of these are true.
C) The lattice energy for a solid with 2+ and 2- ions should be two times that for a solid with 1+ and 1- ions.
In the molecule C2H4 the valence orbitals of the carbon atoms are assumed to be A) not hybridized. B) sp hybridized. C) sp2 hybridized. D) sp3 hybridized. E) dsp hybridized.
C) sp2 hybridized
Which of the following types of molecules has a dipole moment (when polar bonds are present)? A) linear molecules with two identical bonds B) tetrahedral molecules (four identical bonds equally spaced) C) trigonal pyramid molecules (three identical bonds) D) trigonal planar molecules (three identical bonds equally spaced) E) None has a dipole moment.
C) trigonal pyramid molecules (three identical bonds)
36Which one of the following Lewis dot formula is incorrect?
C2H4
52Which of the following molecules cannot exist?
CF3
Which of the following compounds is miscible with water? a. CH3OH b. CH4 c. C6H6 d. CH3CH2OCH2CH
CH3OH
Which compound below is not capable of forming hydrogen bonds? a. CH4 b. NH3 c. H2O d. HF
CH4
20 What is the formula for the binary compound of calcium and bromine?
CaBr2
Which process does not illustrate a decrease in entropy? a. Na(s) + Br2(l) -> 2 NaBr(s) b. CaCO3(s) -> CaO(s) + CO2(g) c. NH3(aq) + H2S(g) -> (NH4)2S(aq) d. AgNO3(aq) + KCl (aq) -> AgCl(s) + KNO3(aq)
CaCO3(s) -> CaO(s) + CO2(g)
No
Catalysts have ___ affect on enthalpy
reaction mechanism
Catalysts provide an alternate ___ that has lower activation energy
65Which of the following compounds does not contain both ionic and covalent bonding?
Cbr4
Which law states that the volume and absolute temperature of a fixed quantity of gas are directly proportional under constant pressure conditions?
Charles's law
14 Which response includes all of the species listed below that have the electronic configuration 1s2 2s2 2p6 3s2 3p6? Cl-, Na+, K+, Ar, P3-
Cl,K+,Ar, and P3-
6. Below are some elements with their number of valence electrons. Which is incorrect?
Cl-5
44Assign a formal charge to each atom of...
Cl=2+, O=1-
87Which molecule is incorrectly matched with the molecular geometry?
ClO3- tetrahedral
26 Which of the following statements about the d-transition metal ions is false?
Cobalt forms a single positive ion, Co2+.
17. Relatively slow rates of chemical reaction are associated with which of the following? (A) The presence of a catalyst (B) High temperature (C) High concentration of reactants (D) Strong bonds in reactant molecules (E) Low activation energy
D
Rate = k[M][N]2 The rate of a certain chemical reaction between substances M and N obeys the rate law above. The reaction is first studied with [M] and [N] each 1 × 10−3 molar. If a new experiment is conducted with [M] and [N] each 2 × 10−3 molar, the reaction rate will increase by a factor of ... (A) 2 (B) 4 (C) 6 (D) 8 (E) 16
D
Which of the following must be true for a reaction for which the activation energy is the same for both the forward and the reverse reactions? (A) A catalyst is present. (B) The reaction order can be obtained directly from the balanced equation. (C) The reaction order is zero. (D) ΔH° for the reaction is zero. (E) ΔS° for the reaction is zero.
D
Calculate the lattice energy for LiF(s) given the following: sublimation energy for Li(s) +166 kJ/mol Delta(Hf) for F(g) +77 kJ/mol first ionization energy of Li(g) +520. kJ/mol electron affinity of F(g) -328 kJ/mol enthalpy of formation of LiF(s) -617 kJ/mol A) 285 kJ/mol B) -650. kJ/mol C) 800. kJ/mol D) -1047 kJ/mol E) None of these
D) -1047 kJ/mol
Which of the following has the smallest radius? A) Cl- B) K+ C) Cr D) Al3+ E) Ar
D) Al3+
Which of the following bonds is least polar? A) C-O B) H-C C) S-Cl D) Br-Br E) They are all nonpolar.
D) Br-Br
Which of the following molecules (or ions) has a dipole moment? A) CO2 B) CO3 2- C) NH4 + D) PF3 E) two of them do
D) PF3
Select the molecule among the following that has a dipole moment. A) CO2 B) SeO3 C) XeF4 D) SF4 E) BeCl2
D) SF4
Which of the following molecules has a dipole moment? A) CH4 B) CCl4 C) CO2 D) SO3 E) none of these
D) SO3
Which of the following bonds would be the most polar without being considered ionic? A) Mg-O B) C-O C) O-O D) Si-O E) N-O
D) Si-O
Which of the following species would be expected to have the highest ionization energy? A) Br- B) Kr C) Se2- D) Sr2+ E) Rb+
D) Sr2+
When electrons in a molecule are not found between a pair of atoms but move throughout the molecule, this is called A) ionic bonding. B) covalent bonding. C) polar covalent bonding. D) delocalization of the electrons.
D) delocalization of the electrons.
10. In which case is the bond polarity incorrect? A) δ+H-F δ - B) δ +K-O δ - C) δ +Mg-H δ - D) δ +Cl-I δ - E) δ +Si-S δ -
D) δ +Cl-I δ -
molar concentration (C)
Defined as the number of moles of solute per litre of solution
state function
Delta H is a
enthaply change
Determines whether the reaction will process once it gets going
heterogeneous catalysts
Different state that reactants
What is the correct order of the following bonds in terms of decreasing polarity? A) N-Cl, P-Cl, As-Cl B) P-Cl, N-Cl, As-Cl C) As-Cl, N-Cl, P-Cl D) P-Cl, As-Cl, N-Cl E) As-Cl, P-Cl, N-Cl
E) As-Cl, P-Cl, N-Cl
Which of the following has the smallest ionic radius? A) Ca2+ B) Cl- C) Li+ D) O2- E) Be2+
E) Be2+
Which of the following groups contains no ionic compounds? A) HCN, NO2, Ca(NO3)2 B) PCl5, LiBr, Zn(OH)2 C) KOH, CCl4, SF4 D) NaH, CaF2, NaNH2 E) CH2O, H2S, NH3
E) CH2O, H2S, NH3
Which of the following statements is incorrect? A) Ionic bonding results from the transfer of electrons from one atom to another. B) Dipole moments result from the unequal distribution of electrons in a molecule. C) The electrons in a polar bond are found nearer to the more electronegative element. D) A molecule with very polar bonds can be nonpolar. E) Linear molecules cannot have a net dipole moment.
E) Linear molecules cannot have a net dipole moment.
Which of the following ionic compounds has the largest lattice energy, i.e., the lattice energy most favorable to a stable lattice? A) CsI B) LiI C) LiF D) CsF E) MgO
E) MgO
Which of the following bonds would be the least polar yet still be considered polar covalent? A) Mg-O B) C-O C) O-O D) Si-O E) N-O
E) N-O
In which pair do both compounds exhibit predominantly ionic bonding? A) PCl5 and HF B) Na2SO3 and BH3 C) KI and O3 D) NaF and H2O E) RbCl and CaO
E) RbCl and CaO
Atoms having greatly differing electronegativities are expected to form: A) no bonds B) polar covalent bonds C) nonpolar covalent bonds D) ionic bonds E) covalent bonds
E. Covalent Bonds
Different rate
Each elementary step will occur at a
23. Which of the following statements about enzymes is false? a. Enzymes do not affect equilibrium. b. Enzymes lower activation energy. c. Enzymes are highly specific. d. Enzymes can convert an endergonic to an exergonic reaction. e. Enzymes can be recycled.
Enzymes can convert an endergonic to an exergonic reaction.
TNT, fireworks
Ex of a fast reaction rate
iron rusting
Ex of a slow reaction rate
Temperature, Concentration, Surface area, nature of the reactants, presence of a catalyst
Factors that affect the rate of a chemical reaction
Pressure/time (Kpa/min or atm/s)
For changes in pressure, units will be
Volume/time (mL/sec or L/h)
For changes in volume of gas, units will be
Doubles
For every 10*C the temperature increases, the reaction rate
21 What is the formula for the binary compound of gallium and chlorine?
GaCl3
Which species is amphiprotic? a. H3PO4 b. H2PO4^1- C. PO4^3- D. none of these
H2PO4^1-
86Which molecule is incorrectly matched with the molecular geometry?
H2S linear
Which of the following correctly lists the acids in order of decreasing strength? a. HClO2 > HClO > HBrO > HIO b. HClO > HBrO > HClO > HClO2 c. HIO > HBrO > HClO > HClO2 d. HClO2 > HIO > HBrO > HClO
HClO2 > HClO > HBrO > HIO
64Which of the following molecules has the most ionic bond character?
HF
47Which response lists all of the correct Lewis dot formulas and no incorrect ones?
I and II
63Which of the following molecules has the most covalent bond character?
IBr
78Which of the following species has a square pyramidal molecular geometry?
IF5
Positive catalyst
If Ea is lowered, reaction will increase
Negative catalyst (or inhibitor)
If Ea is raised, reaction rate will decrease
Products
If a collision is effective the activated complex breaks down into the
pH
If a product or reactant is an acid of bae rate can be measured using changes in
Conductivity
If a product or reactant is an ion, rate can be measured using in
molar concentration
If a product or reactant is in solution, rate can be expressed as change in
volume or pressure
If a reactant or product is a gas, rate can be measure using changes in
Temperature
If a reaction is endothermic or exothermic, rate can be measured using changes in
Large
If a reaction is fast, the value of a rate will be
Balance (mass/time)
If a reaction produces a change in mass, rate can be measured by carrying out the relegation on a
spectrophotometer
If a reaction produces change in colour, rate can be measured visually or using a
unimolecular
If a single molecule breaks down, the molecularity of that step is 1, it is
unlikely
If the activation energy is high, it is ___ that the reaction will occur
Very quickly
If the activation energy is low the reaction will occur
Reactants
If the collision is ineffective the activated complex breaks down into the
effective collision
If the reactant molecules collide with enough emery and in the correct orientation (breaks existing bonds)
ineffective collision
If the reactant molecules do not collide with enough energy or collide in the wrong orientation (existing bonds are not broken)
Small
If the reaction is slow, the value for the rate will be
The reaction mechanism is plausible
If the sum of the steps of the reaction mechanism adds up to give the overall reaction equation & the molar coefficients of the reactants in the RDS agrees with the exponents in the rate law
termolecular
If three particles collide, molecularity of that step is 3, it is
Bimolecular
If two particles collide, the molecularity of that step is 2 , it is
Increase
Increasing temperature causes the reaction rate to
The absolute temperature of a gas is increased four times while maintaining a constant volume. What happens to the pressure of the gas?
It increases by a factor of four.
energy profile (reaction pathway)
It shows the energy changes during the process of a chemical reaction
62Which one of the following compounds contains both ionic and covalent bonding?
KNO3
Which common unit of solution concentration can vary with temperature? a. m b. M c. mass % d. ppb
M
Reversible
Many reactions are ____ and can occur in both directions
8 The negative ion F- has the same electronic configuration as the positive ion _____.
Mg 2+
elementary steps (elementary reactions)
Most reactions proceed as a series of steps called
45Which of the following statements about Lewis structures is false?
N, P, and As can sometimes share more than 8 e-.
13 Which response includes all of the species listed below that have 5 valence electrons? O2-,N,P,C-,F-
N,P,C-
51Which response lists all the molecules below that have one unshared pair of electrons on the central atom, and no other molecules? BCl3, AsF5, NF3, H2S
NF3
Which of the following mixtures could be used to prepare an effective buffer solution ? a. HCl and Kcl b. HNO3 and KNO3 c. Hcl and NH4Cl d. NH3 and NH4Cl
NH3 and NH4Cl
84Which molecule is incorrectly matched with the molecular geometry?
NO2
22 Which one of the formulas below is incorrect?
Na2I
61Which one of the following compounds involves both ionic and covalent bonding?
Na2SO4
n
Number of miles of solute
58Which molecule exhibits resonance?
O3
Which of the following is NOT a weak base? a. NH3 b. NH2OH c. F- d. OH-
OH-
7 An atom of which element below has the most unpaired electrons?
P
43Assign a formal charge to each atom of PH4+
P=1+, H=0
49Which molecule below has only one unshared pairs of electrons in the valence shell of the central atom?
PH3
A large value of the equilbrium constant indicates that when the reaction reaches equilibrium, mostly ____ will be present. A. Reactants B. Product C. Catalysts
Product
7. What type of macromolecule is an enzyme?
Protein
25 Which of the following formulas is incorrect?
Rb2F
Experimentally
Reaction mechanisms are determined
slow
Reaction that occurs over a long period of time
Period of time being studied & Which product or reactant is being measured
Reactions rate depends on the
Positive
Reactions rates are always ____ values because they measure how fast the reaction is proceeding or loving forward
The equilibrium constant expression for a reaction written in one direction is the ---- of the one for the reaction written for the reverse direction A. reciprocal B. square
Reciprocal
Nature is the reactants
Refers to the size of the particles, their state and whether they are charged
2. which Lewis dot formula is incorrect
S
85Which molecule is incorrectly matched with the molecular geometry?
SF4
56Which response contains all the molecules below that violate the octet rule, and no others?
SF4, AsF5, BeI2
57Which response includes all the molecules below that violate the octet rule and only those?
SF6 and BeCl2
83Which molecule is incorrectly matched with the molecular geometry?
SO2 linear
37Which lewis dot formula is incorrect?
SO3 2-
homogeneous catalysts
Same states as reactants
76Which one of the following molecules is octahedral?
SeF6
Inhibitor
Slows down chemical reaction
collision theory
States that in order for a chemical reaction to occur, the reactant atoms or molecules must collide with each other
Kinetic molecular theory of matter (KMT)
States that matter is made up of particles (atoms, ions and molecules) that are in constant motion
catalyst
Substance that increases or decreases the rate of a reaction without being consumed itself
Very high energy and is unstable
The activated complex has
9. Which of the following affects the rate of a reaction? a. ΔS b. ΔG c. ΔH d. The activation energy e. The overall change in free energy
The activation energy
10. The hydrolysis of sucrose to glucose and fructose is exergonic. However, if sucrose is dissolved in water and the solution is kept overnight at room temperature, there is no detectable conversion to glucose and fructose. Why?
The activation energy of the reaction is high.
surface area
The amount of exposed surface of a reactant that is available for collisions
12 Which of the following statements is the best definition of valence electrons?
The electrons occupying the highest energy (outermost ) level.
Rate Determining Step (RDS)
The elementary step with the slowest rate and the highest Ea is the
half-life
The length of time needed for the amount of reactant to decrease by a half
reaction intermediate
The molecules that form during the elementary steps are called the
72Which of the following is not one of the basic ideas of the VSEPR theory?
The number of electron groups is determined by counting the number of lone pairs and the total number of bonds.
Molecularity
The number of particles that collide in an elementary reaction is called
Not changed
The overall enthalpy is _____ by the addition of a catalyst
Initial rate
The rate at the very beginning of the reaction while the concentrations of the reactants are very close to their initial concentrations
instantaneous rate
The rate of a reaction at a single moment in time (tangent)
average rate
The rate of the reaction over a specified period of time
Reaction mexhanism
The series of elementary steps that take place as a reaction process from reactants to products
6. What is a transition state in a chemical reaction?
The state at which the bonds of reactants are unstable
chemical kinetics
The study of reactions rate
When heat is added to ice at zero degrees Celsius, what will happen? a. The temperature will increase b. The temperature will decrease c. The temperature will not change d. A supercritical fluid will form
The temperature will not change
relationship
There is no direct ____ between Ea and H
Which equation is derived from the combined gas law?
V1/T1 = V2/T2
V
Volume of the solution in litres
Rate and molecularity
What parts of the RDS determine the rate and molecularity of the overall reaction
activated complex
With the presence of catalyst, a different ___ is formed
Isopropyl alcohol feels cool on the skin because it has an (X) heat of (Y) a. X = exothermic, Y = vaporization b. X = endothermic, Y = vaporization c. X = exothermic, Y = fusion d. X = endothermic, Y = fusion
X = endothermic, Y = vaporization
75Which of the following molecules has three lone pairs of electrons on the central atom?
XeF2
77Which of the following species has square planar molecular geometry ?
XeF4
entropy decreases when a. a liquid becomes a gas b. a solid becomes a solid c. a gas becomes a solid d. the number of moles of gas increases
a gas becomes a solid
4. An RNA molecule that has enzyme activity is called
a ribozyme.
40The Lewis dot formula for N2 shows
a triple covalent bond
If k is the rate constant of a first-order reaction, the half-life of the reaction is a. 0.693/k. b. 0.693k. c. k/2 d. 2k
a. 0.693/k.
At 298 K, k = 1.36 10-7 sec-1. At 323 K, k = 2.72 10-6 sec-1. The energy of activation for this reaction is a. 100 kJ/mole. b. 310 kJ/mole. c. 690 kJ/mole. d. 1000 kJ/mole.
a. 100 kJ/mole.
20. Binding of substrate to the active site of an enzyme is
a. reversible.
2. The ΔG of a reaction tells us all of the following except for a. the rate of the reaction. b. the direction of the reaction. c. whether the reaction is exergonic or endergonic. d. whether the reaction requires or releases energy. e. whether a higher free energy is in the product or in the reactants.
a. the rate of the reaction.
Reaction: W + X Y + Z Rate = k[W] The order of this reaction with respect to X is a. zeroth. b. first. c. second. d. third.
a. zeroth.
A lewis base is a. a proton donor b. a proton acceptor c. an electron-pair donor d. an electron-pair acceptor
an electron-pair donor
In a reaction mechanism, a species that is produces in an early step and consumed in a later step called __________. a. a byproduct b. a catalyst c. an intermediate d. a reactant
an intermediate
74The molecular geometry of the hydrogen sulfide molecule is ___________.
angular
Select the statement that BEST describes a system at equilibrium a. the reaction is complete because all reactants have become products b. the reaction has stopped because all of the catalyst has been used c. as soon as product molecules form, other molecules of product become reactants d. the reaction stops when the amounts of reactants and products reach equilibrium
as soon as product molecules form, other molecules of product become reactants
The value of the rate constant (k) for a first-order reaction is 0.010 sec-1. What is the half-life of this reaction? a. 10 seconds b. 69 seconds c. 100 seconds d. 690 seconds
b. 69 seconds
The relationship that allows us to study changes in concentration by measuring the absorption of light is a. Rate = k[A][B]. b. A = εbc. c. ln[A] t = -kt + ln[A]0. d. t ½ = 0.693/k.
b. A = εbc.
25. Which of the following statements about the enzyme amylase, which hydrolyzes starch to its component glucose molecules, is false? a. Amylase changes shape when it binds to starch. b. Amylase increases the activation energy of starch hydrolysis. c. The active site of amylase is highly specific for starch. d. Amylase may act by orienting the starch, inducing strain on the bonds holding the glucose molecules together or temporarily adding chemical groups during the reaction. e. One amylase enzyme can carry out many repeated hydrolysis reactions.
b. Amylase increases the activation energy of starch hydrolysis.
1. In a reaction mechanism, a species on the reactant side initially that is consumed in an early step and regenerated in a later step is called ___. a. a byproduct b. a catalyst c. an intermediate d. a reactant
b. a catalyst
Over time, the rate of most chemical reactions tends to _______. a. Increase b. decrease c. remain constant d. oscillate
b. decrease
22. The enzyme sucrase increases the rate at which sucrose is broken down into glucose and fructose. Sucrase works by a. increasing the amount of free energy of the reaction. b. lowering the activation energy of the reaction. c. decreasing the equilibrium constant of the reaction. d. supplying energy to speed up the reaction. e. changing the shape of the active site.
b. lowering the activation energy of the reaction.
28. In order to determine if a reaction is at "saturation," you would add _______ and determine if the reaction rate _______. a. ATP; increases b. more substrate; increases c. a competitive inhibitor; decreases d. a downstream product; decreases e. a noncompetitive inhibitor; decreases
b. more substrate; increases
Reaction: A + B C + D Rate = k[A][B] The overall order of this reaction is a. first. b. second. c. third. d. fourth.
b. second.
16. The molecules that are acted on by an enzyme are called
b. substrates.
27 The internuclear distance at which the attractive and repulsive force s balance in a covalent bond is called the _____.
bond length
A + B products, Rate = k[A], k = 0.010 sec-1, Initial [A] = .100 M, Final [A] = .00100 M How long will this take? a. 69 seconds b. 138 seconds c. 460 seconds d. 690 seconds
c. 460 seconds
Rate = k[A]2, Initial [A] = 0.100 M, k = 0.0214 M-1 sec-1 What is the half-life of this second-order reaction? a. 69 seconds b. 138 seconds c. 460 seconds d. 690 seconds
c. 460 seconds
21. Which of the following is an enzyme? a. Manganese dioxide b. Hemoglobin c. Catalase d. Hydrogen peroxide e. Malathion
c. Catalase
Select the incorrect statement. a. The exponents in a rate law are taken from the coefficients in the balanced reaction. b. For a first-order reaction, the plot of ln[A] versus time is linear. c. For a zero-order reaction, the plot of [A] versus time is a parabola. d. The slope of 1/[A] versus time is the rate constant of a second-order reaction.
c. For a zero-order reaction, the plot of [A] versus time is a parabola.
12. Trypsin and elastase are both enzymes that catalyze hydrolysis of peptide bonds. But trypsin only cuts next to lysine and elastase only cuts next to alanine. Why? a. Trypsin is a protein, and elastase is not. b. ΔG for the two reactions is different. c. The shape of the active site for the two enzymes is different. d. One of the reactions is endergonic, and the other is exergonic. e. Hydrolysis of lysine bonds requires water; hydrolysis of alanine bonds does not.
c. The shape of the active site for the two enzymes is different.
29. The enzyme hexokinase converts glucose to glucose-6-phosphate in the presence of ATP. In order to determine the efficiency of hexokinase, you wish to conduct an experiment to calculate its "turnover number." To do so you would set up a. a reaction with a maximum amount of hexokinase at optimal pH and temperature. b. a reaction with a known amount of enzyme and saturation levels of glucose-6-phosphate at optimal pH and temperature. c. a reaction with a known amount of enzyme and saturation levels of glucose at optimal pH and temperature. d. multiple reactions at varying pH levels but with a constant amount of glucose, a constant temperature, and a known amount of enzyme. e. multiple reactions with varying temperatures but a constant amount of glucose, constant pH levels, and a known amount of enzyme.
c. a reaction with a known amount of enzyme and saturation levels of glucose at optimal pH and temperature.
In a reaction mechanism, a species that is produced in an early step and consumed in a later step is called ___. a. a byproduct b. a catalyst c. an intermediate d. a reactant
c. an intermediate
If tripling the concentration of reactant A multiplies the rate by a factor of nine, the reaction is _______ order in A. a. zeroth b. first c. second d. third
c. second
Charles's law Gay-Lussac's law Boyle's law
d b e
Consider the reaction A2 + 3 B2 2 AB3. If ΔA is -0.750 M/min, then ΔB is a. -0.750 M/min. b. -0.225 M/min. c. -0.250 M/min. d. -2.25 M/min
d. -2.25 M/min
Rate = k[A]2, Initial [A] = 0.100 M, k = 0.0214 M-1 sec-1 After 1.00 hour, what is the concentration of reactant A? a. 0.0500 M b. 0.0250 M c. 0.0189 M d. 0.0115 M
d. 0.0115 M
Adding a catalyst increases the rate of a chemical reaction because the presence of the catalyst a. Increases molecular velocities. b. increases molecular collisions. c. decreases energy of activation. d. All of the above
d. All of the above
The rate of a reaction can be increased by a. Increasing reactant concentrations. b. increasing the temperature. c. adding a suitable catalyst. d. All of the above
d. All of the above
The minimum energy that a collision between molecules must have for a reaction to occur is called the a. initial energy. b. internal energy. c. external energy. d. energy of activation.
d. energy of activation.
18. The enzyme glyceraldehyde 3-phosphate dehydrogenase catalyzes the reaction glyceraldehyde 3-phosphate → 1,3-diphosphoglycerate. The binding of the glyceraldehyde 3-phosphate to the enzyme creates a(n) a. transition state. b. activation groove. c. catalyst. d. enzyme-substrate complex. e. energy barrier.
d. enzyme-substrate complex.
The time required for the concentration of a reactant to be reduced to half of its initial value is called the a. midpoint of the reaction. b. equivalence point of the reaction. c. half-rate of the reaction. d. half-life of the reaction.
d. half-life of the reaction.
The rate-determining step is the _______ step in a reaction mechanism. a. first b. last c. fastest d. slowest
d. slowest
19. The enzyme glucose oxidase binds the six-carbon sugar glucose and catalyzes its conversion to glucono-1,4-actone. Mannose is also a six-carbon sugar, but glucose oxidase cannot bind mannose. The specificity of glucose oxidase is based on the a. free energy of the transition state. b. activation energy of the reaction. c. change in free energy of the reaction. d. three-dimensional shape and structure of the active site. e. rate constant of the reaction.
d. three-dimensional shape and structure of the active site.
The hybridization of the central atom in KrF4O is:
d2sp3
over time, the rate of most chemical reactions tends to __________. a. increase b. decrease c. remain constant d. oscillate
decrease
Rate of a chemical reaction---- while the rate constant ---- during the progress of a chemical reaction. A. decreases, decreases B. increases, decreases C. decreases, remain constant
decreases, remain constant
---- the volume causes the reaction to shift in the direction that has the fewer moles of gas particles A. increasing B. decreasing
decreasing
The half life of a second order reaction--- depend on the concentration A. does not B. does
does
The hybridization of the central atom in XeCl3+ is:
dp3
1. Which of the following reactions will go the furthest toward completion? a. A reaction with a ΔG of zero b. A reaction with a ΔG of +2 kcal/mol c. A reaction with a ΔG of +12 kcal/mol d. A reaction with a ΔG of ‒2 kcal/mol e. A reaction with a ΔG of ‒12 kcal/mol
e. A reaction with a ΔG of ‒12 kcal/mol
15. In some cases, a substrate-enzyme complex is stabilized by a. hydrogen bonds. b. covalent bonds. c. ionic attractions. d. hydrophobic interactions. e. All of the above
e. All of the above
26. Enzymes may catalyze a reaction by _______ the substrates. a. orienting b. inducing strain in c. adding chemical groups to d. adding charges to e. All of the above
e. All of the above
11. Which of the following will not increase the rate of conversion of A to product B in the presence of enzyme C? a. An increase in enzyme concentration b. An increase in temperature to the optimum for the reaction c. An increase in substrate concentration d. The addition of a nonbiological catalyst that can carry out the same reaction e. The addition of D, that can compete with A for binding on the active site
e. The addition of D, that can compete with A for binding on the active site
24. The presence of a catalyst affects the a. amount of activation energy required. b. overall energy change, or ΔG. c. energy of the reactants. d. energy of the products. e. free energy of the transition state.
e. free energy of the transition state.
17. The enzyme a-amylase increases the rate at which starch is broken down into smaller oligosaccharides by _______ of the reaction. a. decreasing the equilibrium constant b. increasing the change in free energy c. decreasing the change in free energy d. increasing the change in entropy e. lowering the activation energy
e. lowering the activation energy
The explanation for the differences in properties between ionic and metallic solids is that __________. a. ionic solids are often water soluble b. electrons can move freely in metals, but not in ionic compounds c. the nuclei are in a fixed position in ionic solids, but not in metals d. None of these are correct
electrons can move freely in metals, but not in ionic compounds
The Minimum energy that a collision between molecules must have a reaction to occur is called the a. initial energy b. internal energy c. external energy d. energy of activation
energy of activation
at equilibrium, the rate of the forward reaction is __________ the rate of the reverse reaction. a. equal to b. slower than c. faster than d. the reverse of
equal to
c = n/V
formula for molar concentration
The constant "A" in the Arrhenius equation is known as ----. A. activation energy B. frequency factor C. rate constant
frequency factor
If two gases are present in a container, the total pressure in the container is equal to
he sum of the pressures that are exerted by each of the two gases.
8. In a chemical reaction, transition-state intermediates have free energies that are
higher than either the reactants or the products.
Select the best acid or base to pair with its conjugate salt to prepare a buffer with pH ~ 8.5 a. acetic acid, Ka = 1.8e-5 b . ammonia, Kb ~ 1.8e-5 c. hydroxylamine, Kb = 1.1e-8 d. critic acid, Ka = 7.4e-4
hydroxylamine, Kb = 1.1e-8
CO2 + H2 <-> CO + H2O If all species are gases and H2 is added, the concentration of CO at equilibrium will a. increase b. decrease c. remain unchanged d. disappear
increase
CO2 + H2 <-> CO + H2O Increasing the temperature of this endothermic reaction will __________ the value of K. a. decrease b. increase c. not change d. change unpredictably
increase
CO2+H2 <--->CO H2O If all species are gases and H2 is added, the equilibrium will shift to right, and the amount of CO present at equilibrium will: A. increase B. decrease
increase
K = 2.39 for the gaseous reaction SO2Cl2 <-> SO2 + Cl2. for the mixture where Q = 5.21 to reach equilibrium, the concentration of SO2Cl2 must ___________. a. increase b. decrease c. remain the same d. change in a way that cannot be predicted
increase
If thr reaction is endothermic,___ the reaction temperature results in an increase in K. a. increasing b. decreasing
increasing
The rule of "like dissolves like" refers to similarities between ___________ of miscible liquids a. molecular weights b. shapes c. intermolecular attractive forces d. densities
intermolecular attractive forces
all spontaneous processes are a. reversible b. isothermal c. irreversible d. exothermic
irreversible
How will the volume of a gas be affected if the pressure is tripled, but the temperature remains the same? Why might a rubber raft burst if it is left in the sun on a summer day?
it is decreased to one third of its original volume temperature increases, causing interior pressure to increase
If you decreased the volume of a sample of gas by a factor of three while maintaining a constant pressure, how would the absolute temperature of the gas be affected? A gas at 300 K and 4.0 atm is moved to a new location with a temperature of 250 K. The volume changes from 5.5 L to 2.0 L. What is the pressure of the gas at the new location? What is the partial pressure of 0.50 mol Ne gas combined with 1.20 mol Kr gas at a final pressure of 730 torr?
it would decrease threefold 9.2 atm 215 torr
82What is the geometry of a carbon atom involved in a triple bond?
linear
89predict the molecular geometry of carbon disulfide, CS2.
linear
Which force below increases in strength as the molecular weight of the compound increases? a. Hydrogen Bonding b. ion-dipole forces c. dipole-dipole forces d. london dispersion forces
london dispersion forces
18 Consider the formation of one formula until of Li3N from neutral atoms. In the process, each lithium atom ____ electron(s) and each nitrogen atom ____ electron(s).
loses one; gains three
Assuming that the frequency factor is nearly constant, higher the activation energy of a chemical reaction, --- is the rate constant. A. higher B. lower C. zero
lower
Which solid is incorrectly paired with the bonding description? a. ionic solid; electrostatic attractions b. metallic solid; delocalized electrons c. molecular solids; dispersion, dipole, and hydrogen bonds d. network solid; transferred electrons
network solid; transferred electrons
If the enthalpy change is positive and the entropy change is negative the reaction is a. spontaneous at all temperatures b. non-spontaneous at all temperatures c. spontaneous at low temperatures d. spontaneous at high temperatures
non-spontaneous at all temperatures
What are the units of the rate constant for a reaction with a law of: Rate= k[A] A. M s B. M^2 s C. none of these
none of these
30Draw the Lewis dot formula for PCl3. The number of unshared pairs of electrons in the outer shell of the central atom is _____.
one
38The number of unshared pairs of electrons in the outer shell of arsenic in AsF3 is ______.
one
48How many lone pairs of electrons are there on the S atom in the SCl4 molecule?
one
42which of the following is NOT shown in the lewis structure for NH2?
one lone pair is on each H atom
Two solutions that are isotonic have the same a. density b. volume c. vapor pressure d. osmotic pressure
osmotic pressure
14. An active site is the
part of the enzyme that binds with a substrate.
A scientist is measuring the pressure that is exerted by each of the following gases in the atmosphere: carbon dioxide, oxygen, and nitrogen. Which term most likely describes what she is measuring?
partial pressure
The incomplete table below shows selected characteristics of gas laws. What are the variables in Gay-Lussac's law?
pressure and temperature
At equilibrium, the equalibrim constant is equal to : A. reactant/ product B. product/ reactant
product/ reactant
If the value of the equilibrium constant is large, then at equilibrium mostly __________ will be present. a. reactants b. products c. catalysts d. water
products
73the molecular geometry of the hydrogen sulfide molecule is _________.
pyramidal
3. The rate of a chemical reaction is the measure of how
quickly the reaction reaches equilibrium.
For a chemical reaction the Q>K. This indicates--- A. reaction goes to the left B. Reaction goes to the right C. Reaction is at equilibrium
reaction goes to the left
For a chemical reaction the Q<K. This indicates,--- A. reaction goes to the left B. Reaction goes to the right C. Reaction is at equilibrium
reaction goes to the right
13. The statement "enzymes are highly specific" means that specific
reactions involving specific substrates are catalyzed by specific enzymes.
Ni(CO)4 (g) <-> Ni(s) + 4 CO(g) adding nickel to this reaction will cause the equilibrium to a. shift towards products b. shift towards products c. remain unchanged d. change based on the amount added
remain unchanged
If tripling the concentration of reactant A multiplies the rate by a factor of nine, the reaction is __________ order in A. a. zeroth b. first c. second d. third
second
In a set of experiments the initial rate of a chemical reaction for a concentration of .10 M reactant was .015M/s. When the reactants concentration was doubled to .2M, the initial rate was .060 M/s. This observation indicates the order of reaction was ---. A. zero B. first C. second
second
Reaction: A + B -> C + D Rate = k[A][B] The overall order of this reaction is a. first b. second c. third d. fourth
second
39Draw the dot formula for ethylene C2H4. Each carbon-hydrogen bond is a _____ bond and each carbon-carbon bond is a ________ bond.
single, double
The rate determining step is the __________ step in a reaction mechanism. a. first b. last c. fastest d. slowest
slowest
The hybridization of the phosphorus atom in the cation PH2+ is:
sp2
5. The phosphorylation of glucose to glucose-6-phospate has a ΔG of +4.0 kcal/mol. If hexokinase is added to speed up the rate of this reaction, the ΔG will
stay the same.
The incomplete table below shows selected characteristics of gas laws. Which constants would most likely be filled in the first row of the table?
temperature and moles of gas
The gas in the piston is being heated, and the piston has moved upward. The observation will be summarized in a row of the incomplete table below. What are the variables for this piston?
temperature and volume
71The electronic geometry is
the arrangement of regions of high electron density around the central atom in a molecule .
Give the direction of the reaction, if K>>1 A. the forward reaction is favored B. The reverse reaction is favored C. neither reaction is favored
the forward reaction is favored
Which quantity is NOT used in calculating the total energy involved in converting 50g of ice at 0ºC to water at 95ºC? a. the mass of the sample b. the heat of fusion of ice c. the heat capacity of liquid water d. the heat of vaporization of water
the heat of vaporization of water
activation energy
the minimum amount of energy required for a successful collision (determines the reaction rate)
Kp = Kc when a. the reaction is at equilibrium b. the reaction is exothermic c. all of the gases present are at the same pressure d. the number of moles of gas on both sides of the balanced equation is the same
the number of moles of gas on both sides of the balanced equation is the same
30. Enzymatic reactions can become saturated as substrate concentration increases because
there are limited enzyme molecules present.
80What is the geometry of a carbon atom involving in one double bond?
trigonal planar
90Predict the molecular geometry of arsine, AsH3.
trigonal pyramidal
Equilibrium constant has no units A. true B. false
true
31The number of unshared pairs of electrons in the outer shell of sulfur in H2s is _____.
two
41The lewis dot formula for CO2 shows
two double covalent bonds.
The solubility of KCl is 34 g/ 100 mL water. A 100 mL sample containing 29.2 g of KCl is __________. a. saturated b. supersaturated c. unsaturated d. polysaturated
unsaturated
70The electrons in the outer shell of an atom are involved in bonding. Another name for the outer shell is ______.
valence shell
The substance that would evaporate most easily is one with __________ intermolecular forces and a __________ molar mass. a. weak; large b. weak; small c. strong; large d. strong; small
weak; small
the stronger the acid, the __________ its conjugate base. Acids and bases react to form their __________ conjugates. a. stronger; stronger b. stronger; weaker c. weaker; stronger d. weaker; weaker
weaker; weaker
29Draw the Lewis dot formula for CO2. The number of unshared pairs of electron in the outer shell of the central atom is _____.
zero
Particularly in a --- order reaction, the rate of the reaction is independent of the concentration of the reactant. A. second B. first C. zero
zero
Reaction: W + X -> Y + Z Rate = k[W] The order of this reaction with respect to X is a. zeroth b. first c. second d. third
zeroth