Chem quiz 3

A compound used in the treatment of manic depression has the formula Li2CO3. Which of the following is the correct name for this compound? a. lithium carbonate b. dilithium carbonate c. lithium carbon trioxide d. lithium carboxide

A

How many main types of chemical bonds exist? a. 2 b. 4 c. 1 d. 3

A

How many molecules are present in one mole of water, H2O? a. 6.02 ´ 10^23 b. 1.66 ´ 10^-24 c. 3.24 ´ 10^23 d. 3.00 ´ 10^-23

A

In the reaction Pb(s) + 2 Ag+(aq) ® Pb2+(aq) + 2 Ag(s) which species is reduced? a. Ag+(aq) b. Ag(s) c. Pb(s) d. Pb2+(aq)

A

The following represents carbonic acid, an important part of the buffer system in blood. How many total valence electrons were used in constructing this structure? a. 24 b. 12 c. 17 d. 22 e. none of these

A

What is the correct name for K2HPO4? a. potassium hydrogen phosphate b. potassium hydrogen phosphoxide c. potassium dihydrogen phosphate d. dipotassium hydrogen phosphate

A

What is the formula of the compound formed by an iron(III) ion and oxygen? a. Fe2O3 b. FeO2 c. FeO d. Fe3O2

A

What is the name of NO2? a. nitrogen dioxide b. nitrous oxide c. nitrogen oxide d. nitrogen oxygen

A

When solutions of AgNO3 and NaCl react, the balanced molecular equation is: AgNO3(aq) + NaCl(aq) ® AgCl(s) + NaNO3(aq) How much AgCl is produced when 3.10 g of AgNO3 and 3.10 g of NaCl react? a. 2.62 b. 4.17 g c. 6.20 g d. 1.55 g

A

When solutions of H2SO4 and NaOH react, the balanced molecular equation is: H2SO4(aq) + 2 NaOH(aq) ® Na2SO4(aq) + 2 H2O(l) How much Na2SO4 is obtained when 4.00 g of H2SO4 reacts with 2.00 g of NaOH? a. 3.55 g b. 4.20 g c. 0.650 g d. 2.98 g

A

When we name a molecular binary compound which of the following is true? a. We name the less electronegative element first. b. The element which has more atoms in the molecule is named first. c. We name the more electronegative element first. d. We name the elements in alphabetical order.

A

Which of the following bonds is the most polar? a. C—F b. C—H c. C—N d. C—O

A

Which of the following elements is most electronegative? a. O b. N c. B d. C

A

Which of the following increases as temperature increases? a. kinetic energy b. nuclear forces c. potential energy d. none of these

A

Which of the following is an example of a molecular solid? a. P1V1/T1 = P2V2/T2 b. P1V1/T2 = P2V2/T1 c. P1V2/T1 = P2V1/T2 d. P1V2/T2 = P2V1/T1

A

Which of the following is reduction? a. gain of electrons b. loss of hydrogen c. gain of oxygen d. none of these

A

Which of the following is the correct way to write the formula of the compound formed between the barium ion and the sulfate ion? a. BaSO4 b. Ba(SO4)2 c. Ba2(SO4)2 d. Ba2SO4

A

Which of the following is true of London dispersion forces? a. They increase as the number of electrons in a molecule increases. b. They are only present in some molecules. c. Both a and b are correct. d. Neither a nor b is correct.

A

Which of the following sulfides is soluble in water? a. K2S b. PbS c. FeS d. Ag2S

A

Which regions of a heating curve correspond to regions where two phases of a material are present? a. horizontal regions b. regions with negative slope c. regions with positive slope d. It depends on the material.

A

A covalent bond is associated with which of the following? a. interactions between nuclei b. the sharing of electrons c. the transfer of electrons d. all of these

B

How many molecules are present in one mole of glucose, C6H12O6? a. 3.34 ´ 10^21 b. 6.02 ´ 10^23 c. 6.92 ´10^-26 d. 1.44 ´ 10^25

B

If you need a sample of 2.84 mol of Na2S, how many grams do you need? a. 78.1 g b. 222 g c. 2.84 g d. 0.00451 g

B

In the reaction CH2O(g) + O2(g) ® HCOOH(g) + H2O(g) which species is reduced? a. CH2O(g) b. O2(g) c. HCOOH(g) d. H2O(g)

B

In the reaction Pb(s) + 2 Ag+(aq) ® Pb2+(aq) + 2 Ag(s) which species is reducing agent? a. Ag+(aq) b. Pb(s) c. Pb2+(aq) d. Ag(s)

B

In which of the following molecules does the carbon atom have a nearly trigonal planar distribution of electron density? a. C2H2 b. C2H4 c. C2H6 d. none of these

B

The tin compound used to strengthen teeth has the formula SnF2. Which of the following is the common name for this compound? a. stannic fluoride b. tin fluoride c. tin(II) fluorine d. stannous fluoride

D

The toxic gas hydrogen cyanide has the formula HCN. How many electrons must be shown in the Lewis structure of hydrogen cyanide? a. 6 b. 2 c. 12 d. 10

D

What is the correct systematic name for the compound with the formula CuCl2? a. cupric chloride b. copper(II) chlorine c. cuprous chloride d. copper(II) chloride

D

When a solution of ammonium chloride, NH4Cl, is added to a solution of lead(II) nitrate, Pb(NO3)2, a white precipitate of lead chloride, PbCl2, forms. Which of the following is the total ionic equation for this reaction? a. Pb2+(aq) + 2 Cl-(aq) ® PbCl2(s) b. Pb2+(aq) + Cl22-(aq) ® PbCl2(s) c. 2 NH4Cl(aq) + Pb(NO3)2(aq) ® PbCl2(s) + 2 NH4NO3(aq) d. 2 NH4+(aq) + 2 Cl-(aq) + Pb2+(aq) + 2 NO3-(aq) ® PbCl2(s) + 2 NH4+(aq) + 2 NO3-(aq)

D

Which of the following does not affect the boiling point of a liquid? a. the formula weight of the liquid molecules b. the shape of the liquid molecules c. the intermolecular forces between the liquid molecules d. None, all of the above affect the boiling point.

D

Which of the following is a unit of pressure? a. mm of Hg b. pascals c. torr d. They are all units of pressure.

D

Which of the following is the correct unit for formula weight? a. grams b. ounces c. pounds d. atomic mass units

D

Which of the following is true about a molecule which contains three polar bonds which have the same degree of polarity? a. The molecule will always be polar. b. The molecule will never be polar. c. The molecule will be polar if the electron distribution is trigonal planar. d. None of the above is true.

D

Which of the following molecules cannot engage in hydrogen bonding? a. SiH4 b. PH3 c. H2S d. all of these

D

Sodium sulfite, Na2SO3(aq), is added to wine as an antioxidant since it reacts with the oxygen of the air to form sodium sulfate, Na2SO4(aq). Which of the following is the balanced equation for this reaction? a. Na2SO3(aq) + 2 O(g) ® Na2SO4(aq) b. 2 Na2SO3(aq) + O2(g) ® 2 Na2SO4(aq) c. Na2SO3(aq) + O(g) ® Na2SO4(aq) d. Na2SO3(aq) + O2(g) ® Na2SO4(aq)

B

The chemical formula of rust is Fe2O3. Which of the following is the correct common name for this compound? a. iron oxide b. ferric oxide c. ferrous oxide d. diiron trioxide

B

The specific heat of water is 1.0 cal/g·°C. The heat of vaporization of water is 540 cal/g. Which of the following is true? a. It takes less energy to evaporate one gram of water than it does to heat one gram of water from 0°C to 100°C. b. It takes more energy to evaporate one gram of water than it does to heat one gram of water from 0°C to 100°C. c. It takes the same amount of energy to evaporate one gram of water as it does to heat one gram of water from 0°C to 100°C. d. There is insufficient information to answer the question.

B

The synthesis of a certain drug requires 4 steps. First three steps were relatively easy with percent yields of 97.1%, 94.3% and 92.8% respectively. However, the last step was very difficult with a percent yield of 72.7%. What was the overall percent yield? a. 85.0% b. 61.8% c. 72.7% d. 27. 9%

B

The term molecular weight is strictly correct for which of the following? a. ionic compounds b. covalent compounds c. both a and b d. neither a nor b

B

What is the formula of the compound formed by calcium and fluorine? a. CaF3 b. CaF2 c. CaF d. Ca2F

B

What is the volume occupied by a 8.00 gram sample of molecular oxygen at STP? a. 44.8 L b. 5.60 L c. 11.2 L d. 22.4 L

B

When wine turns sour it is the result of the conversion of ethanol, C2H5OH, to acetic acid, HC2H3O2. Which of the following happens to ethanol in this reaction? a. It is reduced. b. It is oxidized. c. It is both oxidized and reduced. d. It is neither oxidized nor reduced.

B

Which of the following compounds has the largest formula weight? a. sodium acetate b. aluminum acetate c. potassium acetate d. calcium acetate

B

Which of the following molecules is(are) polar? a. BCl3 b. NH3 c. both of them d. neither of them

B

Which of the following symbols is used to denote that two or more representations of a species are resonance structures? a. ¬ b. « c. ®

B

A sample of carbon dioxide occupies 22.4 L at STP. Which of the following statements apply to the sample? a. The sample contains 6.02 ´ 1023 carbon atoms. b. The sample contains 6.02 ´ 1023 molecules. c. Both a. and b are correct. d. Neither a nor b is correct.

C

According to the kinetic molecular theory, which of the following is not true? a. Gas molecules are assumed to have no volume. b. Gas pressure is caused by collisions between gas molecules and the container walls. c. When gas molecules collide they stick together. d. None, all of the above are true.

C

At constant temperature the pressure on a 6.0 L sample of a gas is reduced from 2.0 atm to 1.0 atm. What is the new volume of the gas sample? a. 0.083 L b. 0.33 L c. 12 L d. 3.0 L

C

Formaldehyde has the chemical formula CH2O. How many electrons must be shown in the Lewis structure of formaldehyde? a. 4 b. 8 c. 12 d. 16

C

In the reaction CH2O(g) + O2(g) ® HCOOH(g) + H2O(g) which species is oxidizing agent? a. CH2O(g) b. H2O(g) c. O2(g) d. HCOOH(g)

C

In the reaction Pb(s) + 2 Ag+(aq) ® Pb2+(aq) + 2 Ag(s) which species is oxidized? a. Pb2+(aq) b. Ag+(aq) Correctc. Pb(s) d. Ag(s)

C

In the reaction Pb(s) + 2 Ag+(aq) ® Pb2+(aq) + 2 Ag(s) which species is the oxidizing agent? a. Ag(s) b. Pb(s) c. Ag+(aq) d. Pb2+(aq)

C

Lime, CaO, is produced by the reaction CaCO3(s) ® CaO(s) + CO2(g). What weight of CO2 is obtained by the decomposition of 38.7 g of CaCO3? a. 23.2 g b. 15.5 g c. 17.0 g d. 21.7 g

C

The ammonium ion has the formula NH4+. How many nonbonding electrons must be shown in the Lewis structure of the ammonium ion? a. 4 b. 9 c. 0 d. 8

C

The atomic weight of platinum is less than that of gold. If you have a 10 g sample of each of these metals, which of the following is true? a. You have fewer of atoms of platinum than of gold. b. You have equal numbers of atoms of platinum and gold. c. You have more atoms of platinum than of gold. d. There is insufficient information to determine which of the above is true.

C

What bond angle is most closely associated with a trigonal planar distribution of electron density? a. 109.5° b. 90° c. 120° d. 180°

C

What is the formula weight ammonium carbonate, (NH4)2CO3? a. 138.2 amu b. 108.4 amu c. 96.1 amu d. 78.1 amu

C

What is the molecular weight of sucrose, C12H22O11? a. 360.4 amu b. 319.6 amu c. 342.3 amu d. 180.2 amu

C

What temperature scale should be used if we wish to express Charles's Law as a simple direct proportionality? a. Fahrenheit b. Celsius c. Kelvin d. It makes no difference.

C

Which law applies only to mixtures of gases? a. Charles's law b. Avogadro's law c. Dalton's law d. Boyle's law

C

Which of the following compounds is soluble in water? a. AgBr b. AgI c. AgC2H3O2 d. AgBr

C

Which of the following is the correct formula for dinitrogen trioxide? a. N3O2 b. O3N2 c. N2O3 d. O2N3

C

Which of the following is the correct set of integer coefficients for the balanced equation respectively: ___ C5H12(g) + ___O2(g) ® ___CO2(g) + ___H2O(g) a. 5, 12, 2, 4 b. 5, 1, 8, 6 c. 1, 8, 5, 6 d. 1, 5, 5, 6

C

Which of the following is true of the types attractive forces present in the three states of matter? a. They are the same in liquids and solids, but different in gases. b. They are different in each of the three states. c. They are the same in each of the three states. d. They are the same in gases and liquids, but different in solids.

C

Which of the following will occur if the temperature of a gas is increased from 20 K to 40 K at constant pressure? a. The volume will increase slightly. b. The volume will decrease slightly. c. The volume will double. d. The volume will be halved.

C

You have a sample of 3.01 ´ 1023 atoms of silver. How much does this sample weigh? a. 2.00 g b. 0.0500 g c. 53.9 g d. 107.9 g

C

In a Lewis structure, which of the following atoms can have more than eight electrons associated with it? a. C b. N c. O d. none of these

D

In the reaction CH2O(g) + O2(g) ® HCOOH(g) + H2O(g) which species is oxidized? a. O2(g) b. HCOOH(g) c. H2O(g) d. CH2O(g)

D

In which of the following cases is a polar covalent bond formed? a. when an electron is transferred from one atom to another b. when a metallic element forms a bond with a non-metallic element c. when the electrons of a bond are shared equally by the two atoms d. when the electrons of a bond are shared unequally by the two atoms whose difference in electronegativity is less than 1.9

D

Laughing gas, sometimes called nitrous oxide, has the formula N2O. What is the proper chemical name for nitrous oxide? a. nitrogen oxide b. nitrogen dioxide c. dinitrogen oxygen d. dinitrogen oxide

D

Of the following ions, which always forms soluble compounds? a. Na+ b. NH4+ c. C2H3O2- d. all of these

D

The combined gas law combines which gas laws? a. Boyle's and Charles's b. Boyle's and Gay-Lussac's c. Charles's and Gay-Lussac's d. Boyle's, Charles's and Gay-Lussac's

D

The synthesis of a certain drug requires 3 steps. The percent yield for the steps are 95.2%, 91.4% and 93.8% respectively. What is the overall percent yield? a. 87.0% b. 91.4% c. 89.3% d. 81.6%

D

Consider the following Lewis structure. What is the correct name for this compound? a. phophorus pentachlorine b. monphosphorus pentachloride c. phosphorus chloride d. pentaphosphorus chloride e. phosphorus pentachloride

E