multiple choice
A basketball is inflated to a pressure of 1.90 atm in a 24.0 °C garage. What is the pressure of the basketball outside where the temperature is -1.00°C? a. 1.74 b. 1.8 c. 2.00 d. 2.07
1.74
When the equation below is balanced and all coefficients are reduced to their lowest whole-number terms, the coefficient for O₂ is C₁₀H₁₂O₄S + O₂ → CO₂ + SO₂ +H₂O 6 7 12 14
12
If the percent yield for the following reaction is 65.0%, how many grams of KClO3 are needed to produce 32.0 g of O2? 2 KClO3 → 2 KCl + 3 O2 Molar Mass of KClO3 = 122.55, O2 = 32.00 g/mol 283 g 81.7 g 126 g 53.1 g
126 g
Which of the following is an INCORRECT interpretation of the balanced equation? N2(g) + 2O2(g) -> 2NO2(g) a. 1 g N2 + 2 g O2 -> 2 g NO2 b. 1 molecule N2 + 2 molecules O2 -> 2 molecules NO2 c. 1 L N2 + 2 L O2 -> 2 L NO2 d. 1 mol N2 + 2 mol O2 -> 2 mol NO2
a. 1 g N2 + 2 g O2 -> 2 g NO2
the formula for a salt is XBr. The x-ion in this salt has 46 electrons. the metal x is a. Ag b. Cd c. Pd d. Cu
a. Ag
Magnesium reacts with a certain element to form a compound with the general MgX. What would the most likely formula be for the compound formed between potassium and element x? a. K2X b. KX C. KX2 d. K2X3
a. K2X
Which substance is the limiting reactant when 34g of sulfur reacts with 54 g of oxygen and 68 g of potassium hydroxide according to the following chemical equation? 2 S + 3O2 + 4 KOH -> 2 K2SO4 + 2H2O a. KOH b. S c. O2 d, K2SO4
a. KOH
When heated, most metals will react with air to form oxides. A student conducts an experiment to determine the formula of a metal oxide by collecting the following data: Mass of Crucible 53.120 Mass of crucible + metal (M) 53.701 Mass of crucible + metal oxide 53.855 molar mass of metal 58.9 what is the empirical formula of the metal oxide a. MO b. M2O c. M2O3 d. MO2
a. MO
Place the following gases in order of increasing density at STP F2 NH3 N2O4 Ar a. N2O4 < Ar < F2 < NH3 b. Ar < N2O4 < F2 < NH3 c. NH3 < F2 < Ar < N2O4 d. Ar < F2 < NH3 < N2O4
a. N2O4 < Ar < F2 < NH3
At STP, one mole each of hydrogen, oxygen, fluorine, and krypton a. have different densities b. occupy different volumes c. have the sane mass d. contain 2 x Na representative particles
a. have different densities
The reaction in which fluorine reacts with potassium bromide solution to form potassium fluoride and bromine is which of the following type of reaction? a. single-replacement reaction b. decomposition reaction c. combination reaction d. double-replacement reaction
a. single-replacement reaction
If a sample of nitrogen gas in a sealed container of fixed volume is heated from 25°C to 75°C, the value of which of the following quantities will remain constant? a. the density of nitrogen b. the average speed of the molecules c. the average kinetic energy of the molecules d. the average intensity of a molecular collision with the walls of the container
a. the density of nitrogen
A balloon filled with 0.25 mol of He at 273 K and 1 atm is allowed to rise through the atmosphere. Which of the following explains what happens to the volume of the balloon as it rises from ground level to an altitude where the air temperature is 220 K and the air pressure is 0.1 atm a. the volume will increase because the decrease in air pressure will have a greater effect than the decrease in temperature b. The volume will decrease because the decrease in temperature will have a greater effect than the decrease in air pressure c. the volume will remain unchanged because of the counteracting effects of the decrease in temperature and the decrease in air pressure d. It cannot be determined whether the volume of the balloon will increase, decrease, or remain the same without knowing the initial volume of the balloon
a. the volume will increase because the decrease in air pressure will have a greater effect than the decrease in temperature
H2S has a shape similar to a. water b. carbon dioxide c. nitrogen dioxide d. hydrogen monochloride
a. water
6.0 g of iron is reacted with 6.0 g of water according to the chemical equation shown below. Which one of the following statements is FALSE? 3Fe + 4H2O -> Fe3O4 + 4H2 a. water is the limiting reactant b. Fe3O4 is not a limiting reactant c. 8.29 g of Fe3O4 are produced d. 3.42g of H2O are left over
a. water is the limiting reactant
How many grams of Li3N can be formed from 1.75 moles of Li? Assume excess Nitrogen. 6Li + N2 -> 2Li3N a. 18.3 b. 20.3 c. 58.3 d. 61
b. 20.3
The Fe3+ ion has a. 26 protons and 26 electrons b. 26 protons and 23 electrons c. 23 protons and 26 electrons d. 23 protons and 23 electrons
b. 26 protons and 23 electrons
At STP, 32 L of O2 contains the same number of molecules as a. 22.4 L Ar b. 32 L H2 c. 44.8 L He d. 28 L N2
b. 32 L H2
How many hydrogen atoms are there in 4 molecules of C3H8 a. 8 atoms b. 32 atoms c. 48 atoms d. 2.41 x 10^24
b. 32 atoms
the number of lone pairs in the carbon dioxide molecule is a. 2 b. 4 c. 6 d. 8
b. 4
Which one of the following samples has the greatest mass a. 0.31 mol of C10H16O b. 4.3 mol of iodine vapor, I2 c. 2.5 mol of CH2O d. 9.8 mol of Kr
b. 4.3 mol of iodine vapor, I2
5.60 L of a gas at STP are found to have a mass of 11.0 g. The molar mass of the gas is a. 22.0 b. 44.0 c. 88.0 d. 32.0
b. 44.0
Which of the following statements is INCORRECT a. A single reactant is the identifying characteristic of a decomposition reaction b. A metal placed lower in the activity series of metals can replace another metal placed higher from a compound in a single-replacement reaction. c. Complete combustion has occurred when all the carbon in the product is in the form of carbon dioxide d. One of the products of a double-replacement reaction is a gas that bubbles out of the mixture
b. A metal placed lower in the activity series of metals can replace another metal placed higher from a compound in a single-replacement reaction.
which of the following contains both ionic and covalent bonds a. Cacl2 b. BaSO4 c. CO2
b. BaSO4
At 727.5 mmHg and 57.1 °C, a 4.55 L sample of a hydrocarbon gas has a mass of 6.67 g. What is the formula of the gas? a. C2H6 b. C3H6 c. C3H8 d. C2H4
b. C3H6
Which of the following group of compounds contains only empirical formulas? a. C3H6, NO2, H2O2 b. C5H12, NO2, H2O c. C5H10, N2O4, H2O2, d. C3H8, N2O4, H2O
b. C5H12, NO2, H2O
A white solid is observed when an unknown solution was added to an ammonium hydroxide solution. the unknown solution is a. NaNO3 b. CaCO3 c. BaSO4 d. KCl
b. CaCO3
The lewis diagram of the NO2 molecule is an exception to the octet rule. What type of exception is it? a. too few electrons b. odd number of electrons c. expanded octet d. it is not an exception case
b. odd number of electrons
an ionic bond is best described as a. the sharing of electrons b. the transfer of electrons from one atom to another c. the attraction that holds the atoms together in a polyatomic ion d. the attraction between 2 metal ions
b. the transfer of electrons from one atom to another
Which of the following chemical reactions is redox? a. AgNO3(aq) + NaCl(aq) -> AgCl(s) + NaNO3(aq) b. NaOH(aq) + HCl(aq) -> NaCl(aq) + H20 (l) c. Zn(s) + S(s) -> Zn(s) d. HsSO4(aq) + 2NaOH(aq) -> Na2SO3(aq) + 2H2O(I)
c. Zn(s) + S(s) -> Zn(s)
All of the following are postulates of the kinetic molecular theory of gases EXCEPT a. the gas molecules are in constant motion b. the collisions between molecules are elastic c. at a constant temperature, each molecule has the same kinetic energy d. the volume of the molecules are negligible compared with the volume of the container
c. at a constant temperature, each molecule has the same kinetic energy
the octet rule indicates that a. all of the shells in an atom hold a maximum of 8 electrons b. all of the group A elements have 8 valence electrons c. atoms lose, gain, or share valence electrons to have 8 valence electrons d. the noble gases react with other compounds and get 8 valence electrons
c. atoms lose, gain, or share valence electrons to have 8 valence electrons
A mixture of 1.0 mol He and 1.0 mol Ne are at STP in a rigid container. Which of the following statements is TRUE? a. The mixture has a volume of 22.4 b. Both gases have the same molecular speed c. both gases have the same average kinetic energy d. both gases contribute equally to the density of the mixture under these conditions
c. both gases have the same average kinetic energy
Water has a boiling point of 100C, and alcohol has a boiling point of 78C, even though water is a smaller molecule. This large difference in boiling point is due to a. ionic bonds between water molecules b. covalent bonds in the alcohol molecules c. more hydrogen bonds between water molecule d. weak dipole-dipole attractions in the alcohol molecules
c. more hydrogen bonds between water molecule
Avogadro's number is equal to the following except a. 6.02 x 10^23 representative particles of a substance b. the number of representative particles in 18.0 g of liquid water c. the number of representative particles in a liter of a substance d. one mole of representative particles of a substance
c. the number of representative particles in a liter of a substance
How many moles of NO are formed from 2.50 moles of NO2 if there is plenty of water present 3 NO2 + H2O -> 2 HNO3 + NO a. 3.75 moles NO b. 2.5 moles NO c. 1.67 moles NO d. 0.834 moles NO
d. 0.834 moles NO
A sample of gas (1.50 mol) is contained in a 15.0 L cylinder. The temperature is increased from 100°C to 150°C. The ration of final pressure to initial pressure (p2/p1) is a. 0.667 b. 0.882 c. 1.00 d. 1.13
d. 1.13
A 2g sample of CaO is reacted with 1.93 g of H2O. How many grams of water remain after the reaction is complete? CaO + H2O -> Ca(OH)2 a. 0.00396 b. 0.0714 c. 1.04 d. 1.29
d. 1.29
1.00 g of Re was isolated from 66.9 kg of the ore molybdenite. the percent by mass of this element in the molybdenite was a. 0.660% b. 6.60 x 10^3% c. 1.52% d. 1.52 x 10^-3%
d. 1.52 x 10^-3%
what is the bond angle in SO3? a. 105 b. 107 c. 109.5 d. 120
d. 120
What volume of CO is formed from the complete decomposition of 444g of Ni(CO)4 at 752 torr and 22.0°C? Ni(CO)4->Ni + 4CO a. 11 b. 20.2 c. 63.7 d. 255
d. 255
what is the percent by mass carbon in C3H6O a. 20.7% b. 30.0% c. 41.4% d. 62.0%
d. 62.0%
A syringe initially holds a sample of gas with a volume of 285 mL at 355 K and 1.88 atm. To what temperature must the gas in the syringe be heated/cooled in order to have a volume of 435 mL at 2.50 atm? a. 175 K b. 466 K c. 572 K d. 721 K
d. 721 K
Which intermolecular forces are experienced by NH3? I. LDF II. Dipole-dipole III. Hydrogen bonding a. I only b. II only c. I and II only d. I and III only e. I, II, and III
d. I and III only
Benzene, as depicted above, is a very important molecule in both pure and applied energy. Which of the following can be said about benzene? I. Each carbon-carbon bond is identical II. It is a planar molecule III. Molecules of benzene experience LDF a. III only b. I and II only c. II and III only d. I, II, II
d. I, II, II
Which of the following statements is incorrect regarding a 256 g sample of gaseous sulfur dioxide at 0°C and 760 mmHg pressure a. there are 4 mol of gas present b. the volume of the gas is 89.7 L c. the density of the gas is 2.86 g/L d. There are 4 x 6.02 x 10^23 atoms of oxygen present
d. There are 4 x 6.02 x 10^23 atoms of oxygen present
Double-replacement reactions are generally driven by the formation of a. a precitate b. a gaseous product c. water d. all of the above
d. all of the above
skeleton equations a. may bot be balanced b. do not indicate the conservation of mass c. show the correct formulas of reactants and products in their correct places d. all of the above
d. all of the above
Which of the following best described the cause of hydrogen bonding a. charged particles are held together by electrostatic forces b. molecules collide and the collision creates a momentary dipole c. one side of a molecule has more electron density than the other d. an extremely electron-deficient hydrogen forms a partial bond with a lone pair on a different molecule
d. an extremely electron-deficient hydrogen forms a partial bond with a lone pair on a different molecule
What does the symbol (triangle) in a chemical equation mean? a. yields b. a catalyst is needed c. precipitate d. heat is supplied to the reaction
d. heat is supplied to the reaction
when a solution of lithium chloride and a solution of ammonium sulfate are mixed a. a new salt is formed b. a precipate forms c. a gas is released d. no reaction occurs
d. no reaction occurs
When the limiting reagent in a chemical reaction is completely used, the a. reaction speeds up b. reaction slows down c. excess reactant begins combining d. reaction stops
d. reaction stops
Which statement is true if 12 mol CO and 12 mol Fe2O3 are allowed to react? 3CO + Fe2O3 -> 2Fe + 3CO2 a. the LR is Fe2O3 and 24 mole FE will be formed b. the LR is Fe2O3 and 36 mol CO2 will be formed c. the LR is CO and 3 mol CO2 will be formed d. the LR is CO and 8 mol Fe will be formed
d. the LR is CO and 8 mol Fe will be formed
A molecule contains a central atom with three identical bonds to other atoms and one lone pair. the shape of this molecule is a. bent b. t structure c. trigonal planar d. trigonal pyramid
d. trigonal pyramid
What is the charge on the Sc ions in Sc2O3?
3+
what is the conversion from kcal to kJ
4.184
Which of the following is an atomic element a) Chlorine b)Nitrogen c) Hydrogen d) Calcium
Calcium
An anion always A) has a positive charge. b) forms covalent bonds. c) contains a metal and a nonmetal E) has a negative charge.
E) has a negative charge.
In the following reaction 2 Fe²⁺ + Br₂ → 2 Fe³⁺ + Br⁻ Which species is oxidized Fe²⁺ Br₂ Fe³⁺ Br⁻
Fe²⁺
A balloon originally had a volume of 4.39 L at 44°C and a pressure of 729 torr. the balloon must be cooled to _____°C to reduce its volume to 3.78L at constant pressure a. 0 b. 38 c. 72.9 d. 273
a. 0
A sample of oxygen is collected over water at a total pressure of 616.8 mmHg at 30°C. The vapor pressure of water at 30°C is 31.8 mmHg. The partial pressure of the O2 is a. 0.7697 b. 0.8116 atm c. 0.8534 atm d. 0.9010 atm
a. 0.7697
Which of the following samples has the fewest moles of gas? a. 1.00 L of NH3 at 10°C and 1.00 atm b. 1.00 L of HCL at 20°C and 1.00 atm c. 1.00 L of CH4 at 10°C and 1.00 atm d. 1.00 L of H2 at 0.0°C and 1.20 atm
a. 1.00 L of NH3 at 10°C and 1.00 atm
According to the following reaction, how much energy is released during the reaction of 32.5g B2H6 and 72.5g Cl2? The molar mass of B2H6 is 27.67 B2H6 + 6Cl2 -> 2BCl3 + 6HCl ΔH = -1396 kJ a. 238 kJ b. 1430 kJ c. 429 kJ d. 3070 kJ
a. 238 kJ
Which of the following is connected by a single covalent bond? a. Br2 b. O2 c. CO d. NO
a. Br2
A compound has the empirical formula C2H3O and a molar mass of 129.15. what is the molecular formula a. C6H9O3 b. C7H8O5 c. C9H16O3 d. C8H12O4
a. C6H9O3
Which of the following is not part of the kinetic-molecular theory a. Collisions between gas molecules do not result in the loss of energy b. attractive and repulsive forces between gas molecules are negligible c. gas particles are neither created nor destroyed by ordinary chemical reactions d. the volume occupied by all of the gas molecules in a container is negligible compared to the volume of the container
a. Collisions between gas molecules do not result in the loss of energy
When iron powder is heated in oxygen gas, iron (III) oxide is formed. This reaction comes under which of the following category? a. Combustion reaction b. Decomposition reaction c. Combination reaction d. Single-replacement reaction
a. Combustion reaction
How many liters of NH3 at STP will react with 5.3 g O2 to form NO2 and water 4NH3 + 7O2 -> 4NO2 + 6H2O a. 3.03 b. 2.12 c. 23 d. 77.3
b. 2.12
A vessel with a volume of 23.1 L contains 2.80 g of nitrogen gas, 0.403 g of hydrogen gas, and 79.9 g of argon gas. At 25°C, what is the pressure in the vessel? a. 1.22 atm b. 2.43 atm c. 88.0 atm d. 256.2 atm
b. 2.43 atm
Which of the following contains the greatest mass of oxygen atoms a. 2.9 mol H2O2 b. 2.9 mol KHSO4 c. 2.9 mol Na2S2O3 d. 1.5 mol K2Cr2O7
b. 2.9 mol KHSO4
Sodium sulfate forms several hydrates. A sample of a hydrate is heated until all the water is removed. What is the formula of the original hydrate if it loses 43.0% of its mass when heated a. Na2SO4 H2O b. Na2SO4 6H2O c. Na2SO4 8H2O d. Na2SO4 2H2O
b. Na2SO4 6H2O
What is the most polar bond in the following list a. P-H b. O-H c. C-S d. S-O
b. O-H
Which of the following statements is incorrect? a. Alkali metals tend to form cations with a charge of +1 b. Transition metals tend to form cations with a charge of +3 c. Halogens tend to form anions with a charge of -1 d. Noble gases tend not to form ionic compounds
b. Transition metals tend to form cations with a charge of +3
Which of the following statements about gases is false? a. gases are highly compressible b. all gases are colorless and odorless at room temperature c. gases expand spontaneously to fill the container they are placed in d. distances between molecules of gas are very large compared to bond distances within molecules
b. all gases are colorless and odorless at room temperature
A scuba diver experiences ___ as she descends into the ocean water a. a decrease of 1 atm for each 20 m of depth b. increase of 1 atm for each 10 m of depth c. a decrease of 1 atm for each 10 m of depth d. an increase of 1 atm for each 20 m of depth
b. increase of 1 atm for each 10 m of depth
Use the standard reaction enthalpies given below to determine ΔH°rxn for the following reaction: 4NO (s) + 2O2(g) → 4NO2(g) ΔH°rxn = ? Given: N2 + O2 → 2 NO ΔH°rxn = 183 kJ 1/2N2 + O2 → NO2 ΔH°rxn = 33 kJ a. -150 kJ b. 234 kJ c. -234 kJ d. 117 kJ
c. -234 kJ
A balloon contains 0.76 mol N2, 0.18 mol O2, 0.031 mol He and 0.026 mol H2 at 749 mmHg. What is the partial pressure of O2? a. 20 mmHg b. 23 mmHg c. 140 mmHg d. 570 mmHg
c. 140 mmHg
How many bonding pairs and lone pairs of electrons are there in KrF2 molecule? a. 2 bonding pairs and 0 lone pairs b. 2 bonding pairs and 3 lone pairs c. 2 bonding pairs and 9 lone pairs d. 2 bonding pairs and 12 lone pairs
c. 2 bonding pairs and 9 lone pairs
The pressure exerted by 1.3 mol of gas in a 13 L flask at 22 degrees celcius is ___ kPa a. 2.4 b. 18 c. 250 d. 560
c. 250
what is the molar mass of NiSO4*6H20 a. 154.88 b. 172.88 c. 262.88 d. 106.88
c. 262.88
If 366.7 mL of nitrogen gas, measured at 316.5 mmHg and 24.1°C, reacts with excess iodine according to the following reaction, what mass of nitrogen triiodide is produced? N2 + 3I2 -> 2NI3 a. 1.24 b. 2.47 c. 4.94 d. 60.9
c. 4.94
What volume of nitrous oxide gas, N2O, has the same number of atoms at 9.00 L of neon gas at the same temperature and pressure? a. 2.25 L b. 3.00 L c. 9.00 L d. 36.0 L
c. 9.00 L
Which statements about the viscosity of a liquid is/are true? I. Viscosity increases as temperature decreases II. Viscosity increases as intermolecular forces increase a. I only b. II only c. I and II d. none
c. I and II
A strip of metal X was immersed in a solution of Y2SO4 and a different piece of metal X was immersed in a solution of Z2SO4. After about 5 minutes, metal X was removed from the 2 solutions. Metal X form the first experiment was coated with a brown solid whereas metal X from the second experiment remained unchanged. Rank the three metals, X, Y, and Z in order of activity from most active to least active. a. Y > X > z b. X > Z > Y c. Z > X > Y d. Y > Z > X
c. Z > X > Y
How many moles of NH4+ ions are there in 3 moles of ammonium phosphate a. 1 b. 3 c. 4 d. 9
d. 9
What is the net ionic equation for the reaction between CaCl₂ and AgNO₃? Ag⁺ + NO₃⁻ → AgNO₃ Ca²⁺ + 2NO₃⁻ → Ca(NO₃)₂ Ca²⁺ + 2Cl⁻ → CaCl₂ Ag⁺ + Cl⁻ → AgCl
d. Ag+ + Cl- -> AgCl
Which is the nonpolar molecule? a. CH3F b. H2O c. PCl3 d. CCl4
d. CCl4
Among the elements listed, which one could replace all of the rest as an ion form a compound in aqueous solution? a. Mg b. Fe c. Cu d. Ca
d. Ca
The spectator ions in the reaction ZnCl2(aq) + 2LiOH(aq) -> LiCl(aq) + Zn(OH)2(s) a. Zn2+ and Cl- b. Zn2+ and OH- c. Li+ and OH- d. Li+ and Cl-
d. Li+ and Cl-
what happens to the excess reactant
remains in the solution