CHEM 121 - Quiz 5 to 7 - Study guide

Select the set of coefficients from the response list that correctly balances the equation. __N2 + O2 ® NO a. 1, 1, 2 c. 2, 1, 2 b. 1, 2, 1 d. 3, 1, 2

a. 1, 1, 2

Which of the following pressure relationships is correct? a. 760 torr = 760 mm Hg b. 1 atm = 15.8 psi c. 650 torr = 1 atm d. more than one correct response e. no correct response

a. 760 torr = 760 mm Hg

Compound with a trigonal pyramidal geometry

C )

Which of the following is the correct "setup" for the problem "How many atoms are present in 10.4 g Ge?"

C)

Which of the following is the correct "setup" for the problem "How many grams of H2O will be produced from 2.1 moles of O2 and an excess of H2S?" according to the reaction 2H2S + 3O2 2H2O + 2SO2

C)

Compound that is nonpolar

D)

To determine the formula mass of a compound you should: a. Add up the atomic masses of all the atoms present. b. Add up the atomic masses of all the atoms present and divide by the number of atoms present. c. Add up the atomic numbers of all the atoms present. d. Add up the atomic numbers of all the atoms present and divide by the number of atoms present.

a. Add up the atomic masses of all the atoms present.

For the following intermolecular force descriptios, select the correct name from the response list: Weakest of all intermolecular forces. a. London force c. covalent bond b. hydrogen bond d. dipole-dipole interaction

a. London force

The correct form of the equation for the ideal gas law is a. PV = nRT b. PT = nRV c. P/V = nRT d. PV = n/RT

a. PV = nRT

A volatile liquid would a. have weak attractive forces between molecules b. evaporate "slowly" at room temperature c. have a low vapor pressure at room temperature d. more than one correct response e. no correct response

a. have weak attractive forces between molecules

Which of the following molecular compounds would have a Lewis structure that contains 10 electron dots? a. HCN b. H2O c. NH3 d. CO2

a. HCN

Which of the following sets of elements is arranged in order of decreasing electronegativity? a. O, S, As b. Cl, B, Cl c. Br, Cl, P d. Be, C, O

a. O, S, As

Select the correct number of atoms in one molecule of dichlorine monoxide. a. contains three or fewer atoms b. contains four atoms c. contains five atoms d. contains six or more atoms

a. contains three or fewer atoms

Select the correct number of atoms in one molecule of nitrogen dioxide. a. contains three or fewer atoms b. contains four atoms c. contains five atoms d. contains six or more atoms

a. contains three or fewer atoms

Which of the following is a molecular compound that contains five atoms per molecule? a. germanium tetrabromide b. dinitrogen monoxide c. dinitrogen pentoxide d. nitrogen diselenide

a. germanium tetrabromide

Electronegativity is a concept that is useful along with other concepts in a. predicting the polarity of a bond b. deciding how many electrons are involved in a bond c. formulating a statement of the octet rule d. determining the charge on a polyatomic ion

a. predicting the polarity of a bond

The total number of nonbonding electron pairs present in the Lewis structure of SiH4 is a.zero b. one c. two d. four

a.zero

A gas has a volume of 2.60 liters at a temperature of 87°C and pressure of 1.30 atm. What is the volume of the gas, in liters, at a temperature of 367°C and a pressure of 4.70 atm? a. 0.782 L b. 1.28 L c. 0.405 L d. 9.80 ´ 104 L

b. 1.28 L

How many molecules of CO2 are present in 33.6 g of CO2? a. 1.27 ´ 10 -24 c. 8.90 ´ 10 26 b. 4.60 ´ 10 23 d. 7.22 ´ 10 23

b. 4.60 ´ 10 23

In which of the following liquids would London forces be the predominant intermolecular force? a. HCN b. N2 c. H2S d. IF

b. N2

A gaseous mixture at a total pressure of 1.50 atm contains equal molar amounts of He, Ne, and Ar. At constant temperature CO2 gas is added to the mixture until the total pressure is 3.00 atm. Which of the following is a correct statement concerning partial pressures after the CO2 addition? a. The partial pressure of Ar has doubled. b. The partial pressure of CO2 is three times that of Ne. c. All four gases have equal partial pressures. d. More than one correct response. e. No correct response.

b. The partial pressure of CO2 is three times that of Ne.

The balanced equation 2CO + O2 ® 2CO2 tells us that: a. One gram of O2 will produce two grams of CO2. b. Two molecules of CO will react with one molecule of O2. c. One mole of CO will produce two moles of CO2. d. More than one correct response. e. No correct response.

b. Two molecules of CO will react with one molecule of O2.

Considering change of state descriptions, select the name of the change of state for the opposite of evaporation. a. sublimation b. condensation c. deposition d. freezing

b. condensation

For the following intermolecular force descriptios, select the correct name from the response list: Strongest of all intermolecular forces. a. London force c. covalent bond b. hydrogen bond d. dipole-dipole interaction

b. hydrogen bond

The phrases "particles close together and held in fixed positions" and "completely fills the container" apply, respectively, to a. liquids and solids c. gases and liquids b. solids and gases d. liquids and gases

b. solids and gases

For which of the following pairs of compounds do both members of the pair have names that contain the prefix di-? a. SCl2 and K2O b. CO2 and N2O c. N2O3 and H2S d. more than one correct response e. no correct response

b. CO2 and N2O

In which of the following pairs of bonds is the first listed bond more polar than the second listed bond? a. N-N and N-F b. P-Cl and S-Cl c. C-N and C-F d. more than one correct response e. no correct response

b. P-Cl and S-Cl

What is the geometry of the molecular compound formed by the reaction of sulfur with hydrogen? a. linear b. angular c. trigonal planar d. tetrahedral

b. angular

The formula mass of ammonium phosphite, (NH4)3PO3, is a. 97.01 amu c. 133.09 amu b. 125.01 amu d. 153.11 amu

c. 133.09 amu

A mole of a chemical substance represents a. the mass of the substance that will combine with 12.0 g of carbon b. the mass of the substance that will combine with 100.0 g of oxygen c. 6.02 ´ 1023 chemical particles of the substance d. 6.02 ´ 10-23 grams of the substance

c. 6.02 ´ 1023 chemical particles of the substance

What is the volume, in liters, occupied by 2.12 moles of N2 gas at 0.745 atm pressure and a temperature of 55°C? a. 42.5 L b. 1.3 ´ 10-2 L c. 76.6 L d. 12.8 L

c. 76.6 L

Consider the mathematical expressions for gas laws listed, select the correct name for the law from the response list: P1V1: P2V2 a. Avogadro's law b. Boyle's law c. Charles's law d. combined gas law

c. Charles's law

Consider the mathematical expressions for gas laws listed, select the correct name for the law from the response list: V1T2 = V2T1. a. Avogadro's law b. Boyle's law c. Charles's law d. combined gas law

c. Charles's law

Which of the following statements is not a part of kinetic molecular theory? a. Matter is composed of particles that are in constant motion. b. Particle velocity increases as the temperature increases. c. Particles in a system cannot transfer energy to each other. d. Particle interactions involve electrostatic attractions and repulsions.

c. Particles in a system cannot transfer energy to each other.

Which of the following descriptions apply to matter in the liquid state? a. Temperature change significantly influences the volume. b. Particles are less free to move about than in the solid state. c. Particles transfer energy from one to another through collisions. d. More than one correct response. e. No correct response.

c. Particles transfer energy from one to another through collisions.

The boiling point of a liquid is a. the temperature at which the rate of evaporation and sublimation are equal b. always 200°C or greater c. the temperature at which the pressure over the liquid equals the vapor pressure of the liquid d. the temperature at which liquid-vapor equilibrium is reached

c. the temperature at which the pressure over the liquid equals the vapor pressure of the liquid

Which of the following compounds contains both ionic and covalent bonds? a. SiO2 b. LiI c. LiCN d. PCl3

c. LiCN

For which of the following pairs of elements would the compound formed between them most likely be a molecular compound? a. Li and Br b. Ba and O c. N and S d. Cs and F

c. N and S

In which of the following molecular compounds are all the bonds single bonds? a. CS2 b. CS c. NBr3 d. O2

c. NBr3

Which set of coefficients balances the equation C4H10 + O2 ® CO2 + H2O? a. 1, 6, 4, 5 c. 1, 3, 4, 5 b. 1, 7, 4, 5 d. 2, 13, 8, 10

d. 2, 13, 8, 10

Avogadro's number of sulfur (S) atoms would have a mass of a. 6.02 ´ 10-23 g b. 6.02 ´ 1023 g c. 16 d. 32

d. 32

In the following reaction, how many grams of H2O are produced if 6.13 g of N2H4 react? N2H4 + 3O2 2NO2 + 2H2O a. 1.72 g c. 12.3 g b. 3.45 g d. 6.89 g

d. 6.89 g

Select the correct numerical value for the mass, in grams, of 2.00 moles of CO2 a. 12.0 c. 44.0 b. 24.0 d. 88.0

d. 88.0

Which of the following chemical equations is balanced? a. 2H2 + O2 ® H2O c. KClO3 ® KCl + 3 O2 b. 2SO2 + 2 O2 ® 3 SO3 d. N2 + 3H2 ® 2NH3

d. N2 + 3H2 ® 2NH3

Which of following statements concerning theoretical yield, actual yield, and percent yield is correct? a. Theoretical yield is a calculated number. b. Actual yield is a calculated number. c. A percent yield of greater than 50% is very difficult to obtain. d. Percent yield is calculated by dividing the theoretical yield by the actual yield.

d. Percent yield is calculated by dividing the theoretical yield by the actual yield.

Which of the following statements about intermolecular forces is incorrect? a. They must be overcome in order for molecules to escape from the liquid state into the vapor state. b. They are much weaker than intramolecular forces. c. They are electrostatic in origin. d. They occur within molecules rather than between molecules.

d. They occur within molecules rather than between molecules.

For each of the physical state characterizations, select from the response list the physical state or states to which the characterizations apply: indefinite shape. a. liquid state only b. solid state only c. both liquid and solid states d. both gaseous and liquid states

d. both gaseous and liquid states

Which of the following equations is balanced? a. FeS + 2HBr ® FeBr2 + 2H2S b. PbO2 + 2H2 ® Pb + 2H2O c. Fe2O3 + 3H2 ® 2Fe + 3H2O d. more than one correct response e. no correct response

d. more than one correct response

Given the following electronegativities: Na = 0.9, H = 2.1, Cl = 3.0 which of the following statements is true? a. H2, Cl2, and HCl are polar covalent molecules. b. NaCl is a polar covalent compound and HCl is an ionic compound. c. HCl is a nonpolar covalent compound and Cl2 is a polar covalent molecule. d. Cl2 is a nonpolar covalent molecule and HCl is a polar covalent molecule.

d. Cl2 is a nonpolar covalent molecule and HCl is a polar covalent molecule.

Which of the following statements contrasting covalent bonds and ionic bonds is correct? a. Covalent bonds usually involve two nonmetals and ionic bonds usually involve two metals. b. Covalent bonds usually involve two metals and ionic bonds usually involve a metal and a nonmetal. c. Covalent bonds usually involve a metal and a nonmetal and ionic bonds usually involve two nonmetals. d. Covalent bonds usually involve two nonmetals and ionic bonds usually involve a metal and a nonmetal.

d. Covalent bonds usually involve two nonmetals and ionic bonds usually involve a metal and a nonmetal.

Which of the following statements concerning double covalent bonds is correct? a. They are found only in molecules that contain P or atoms in the third period or higher. b. They are only found in molecules that contain large atoms that can effectively overlap with each other. c. They occur only between atoms containing 2 valence electrons. d. They always involve the sharing of 4 electrons.

d. They always involve the sharing of 4 electrons.

Choose the correct number of electrons in the Lewis structure for NH3. a. zero b. one c. four d. eight

d. eight

In which of the following triatomic molecules or ions are both of the bonds multiple bonds? a. HCN b. CO2 c. NO2- d. more than one correct response e. no correct response

d. more than one correct response

Which of the following is a correct equation for the combined gas law?

e.