Question 1

How many anions are there in 2.50 g of MgBr2?

Accepted Answer

A) 8.18 × 1021 anions 
B) 1.64 × 1022 anions 
C) 4.43 × 1025 anions 
D) 8.87 × 1025 anions 
A) 8.18 × 1021 anions 
B) 1.64 × 1022 anions 
C) 4.43 × 1025 anions 
D) 8.87 × 1025 anions

Question 2

A sample of pure lithium nitrate contains 10.1% lithium by mass. What is the % lithium by mass in a sample of pure lithium carbonate that has twice the mass of the first sample?

Accepted Answer

A) 5.05% 
B) 10.1% 
C) 20.2% 
D) 40.4% 
A) 5.05% 
B) 10.1% 
C) 20.2% 
D) 40.4%

Question 3

Combustion analysis of an unknown compound containing only carbon and hydrogen produced 0.2845 g of CO2 and 0.1451 g of H2O. What is the empirical formula of the compound?

Accepted Answer

A) CH2 
B) C2H5 
C) C4H10 
D) C5H2 
A) CH2 
B) C2H5 
C) C4H10 
D) C5H2

Question 4

Identify the compound with (an)ionic bond(s).

Accepted Answer

A) Ne 
B) CO 
C) O2 
D) H2O 
E) KBr 
A) Ne 
B) CO 
C) O2 
D) H2O 
E) KBr

Question 5

Combustion analysis of 63.8 mg of a C, H, and O-containing compound produced 145.0 mg of CO2 and 59.38 mg of H2O. What is the empirical formula for the compound?

Accepted Answer

A) C5H2O 
B) CHO 
C) C3H6O 
D) C3H7O 
E) C6HO3 
A) C5H2O 
B) CHO 
C) C3H6O 
D) C3H7O 
E) C6HO3

Question 6

Calculate the number of carbon atoms in 76.91 g of benzoic acid, C6H5COOH.

Accepted Answer

A) 6.693 × 1024 
B) 3.793 × 1023 
C) 2.655 × 1024 
D) 3.767 × 1025  
E) 4.488 × 1020 
A) 6.693 × 1024 
B) 3.793 × 1023 
C) 2.655 × 1024 
D) 3.767 × 1025  
E) 4.488 × 1020

Question 7

Determine the molecular formula of a compound that is 49.48% carbon, 5.19% hydrogen, 28.85% nitrogen, and 16.48% oxygen. The molecular weight is 194.19 g mol-1.

Accepted Answer

A) C8H12N4O2 
B) C4H5N2O 
C) C8H10N4O2 
D) C8H10N2O 
A) C8H12N4O2 
B) C4H5N2O 
C) C8H10N4O2 
D) C8H10N2O

Question 8

Identify an ether.

Accepted Answer

A) CH3CH2OCH2CH3 
B) CH3CH2OH 
C) CH3CH2NH2 
D) CH3CH2CH2CH3 
E) CH3COOH 
A) CH3CH2OCH2CH3 
B) CH3CH2OH 
C) CH3CH2NH2 
D) CH3CH2CH2CH3 
E) CH3COOH

Question 9

Which of the following is a formula for the compound iridium(III)bromide tetrahydrate?

Accepted Answer

A) IrBr∙   H2O 
B) IrBr∙4H2O 
C) IrBr3∙4H2O 
D) IBr3∙4H2O 
E) IBr3∙2H2O 
A) IrBr∙   H2O 
B) IrBr∙4H2O 
C) IrBr3∙4H2O 
D) IBr3∙4H2O 
E) IBr3∙2H2O

Question 10

A sample of pure calcium fluoride with a mass of 15.0 g contains 7.70 g of calcium. How much calcium is contained in 40.0 g of calcium fluoride?

Accepted Answer

A) 2.27 g 
B) 7.70 g 
C) 15.0 g 
D) 20.5 g 
A) 2.27 g 
B) 7.70 g 
C) 15.0 g 
D) 20.5 g

Question 11

What is the mass of 9.44 × 1024 molecules of NO2? The molar mass of NO2 is 46.01 g mol-1.

Accepted Answer

A) 205 g 
B) 294 g 
C) 721 g 
D) 341 g 
E) 685 g 
A) 205 g 
B) 294 g 
C) 721 g 
D) 341 g 
E) 685 g

Question 12

In which set do all elements tend to form anions in binary ionic compounds?

Accepted Answer

A) C, S, Pb 
B) K, Fe, Br 
C) Li, Na, K 
D) N, O, I 
A) C, S, Pb 
B) K, Fe, Br 
C) Li, Na, K 
D) N, O, I

Question 13

How many molecules of butane are contained in 25.0 mL of butane? The density of butane is 0.6011 g mL-1 and the molar mass is 58.12 g mol-1.

Accepted Answer

A) 2.59 × 1023 molecules butane 
B) 1.46 × 1027 molecules butane 
C) 6.87 × 1023 molecules butane 
D) 1.56 × 1023 molecules butane 
E) 7.14 × 1025 molecules butane 
A) 2.59 × 1023 molecules butane 
B) 1.46 × 1027 molecules butane 
C) 6.87 × 1023 molecules butane 
D) 1.56 × 1023 molecules butane 
E) 7.14 × 1025 molecules butane

Question 14

Identify the formula for sulfurous acid.

Accepted Answer

A) H2SO3 
B) HSO3 
C) H2SO4 
D) HSO4 
A) H2SO3 
B) HSO3 
C) H2SO4 
D) HSO4

Question 15

Determine the mass percent (to the hundredths place)of H in sodium bicarbonate (NaHCO3).

Accepted Answer

Question 16

How many molecules are in 114.86 g of vitamin C, C6H8O6?

Accepted Answer

A) 1.218 × 1028 
B) 3.927 × 1023 
C) 2.546 × 10-24 
D) 2.977 × 1019 
E) 2.977 × 1022 
A) 1.218 × 1028 
B) 3.927 × 1023 
C) 2.546 × 10-24 
D) 2.977 × 1019 
E) 2.977 × 1022

Question 17

What mass of ethane, CH6, contains the same number of molecules as 3.00 g of trichlorofluoromethane, CCl3F?

Accepted Answer

A) 0.0727 g 
B) 0.655 g 
C) 1.52 g 
D) 13.7 g 
A) 0.0727 g 
B) 0.655 g 
C) 1.52 g 
D) 13.7 g

Question 18

What is the mass of 8.50 × 1022 molecules of NH3?

Accepted Answer

A) 0.00829 g 
B) 0.417 g 
C) 2.40 g 
D) 121 g 
A) 0.00829 g 
B) 0.417 g 
C) 2.40 g 
D) 121 g

Question 19

Identify the formula for the compound formed between potassium and sulfur.

Accepted Answer

A) KS 
B) KS2 
C) K2S 
D) K2SO3 
E) K3S2 
A) KS 
B) KS2 
C) K2S 
D) K2SO3 
E) K3S2

Question 20

Combustion analysis of an unknown hydrocarbon produced the following results: C 52.14%, H 13.13%, O 34.73%. Determine the empirical formula.

Accepted Answer

A) C4H8O2 
B) C4H12O2 
C) C2H6O 
D) C4H6O2 
E) C6H8O4 
A) C4H8O2 
B) C4H12O2 
C) C2H6O 
D) C4H6O2 
E) C6H8O4

Exam 3: Molecules, Compounds, and Nomenclature

How many anions are there in 2.50 g of MgBr2?

A sample of pure lithium nitrate contains 10.1% lithium by mass. What is the % lithium by mass in a sample of pure lithium carbonate that has twice the mass of the first sample?

Combustion analysis of an unknown compound containing only carbon and hydrogen produced 0.2845 g of CO2 and 0.1451 g of H2O. What is the empirical formula of the compound?

Identify the compound with (an)ionic bond(s).

Combustion analysis of 63.8 mg of a C, H, and O-containing compound produced 145.0 mg of CO2 and 59.38 mg of H2O. What is the empirical formula for the compound?

Calculate the number of carbon atoms in 76.91 g of benzoic acid, C6H5COOH.

Determine the molecular formula of a compound that is 49.48% carbon, 5.19% hydrogen, 28.85% nitrogen, and 16.48% oxygen. The molecular weight is 194.19 g mol-1.

Identify an ether.

Which of the following is a formula for the compound iridium(III)bromide tetrahydrate?

A sample of pure calcium fluoride with a mass of 15.0 g contains 7.70 g of calcium. How much calcium is contained in 40.0 g of calcium fluoride?

What is the mass of 9.44 × 1024 molecules of NO2? The molar mass of NO2 is 46.01 g mol-1.

In which set do all elements tend to form anions in binary ionic compounds?

How many molecules of butane are contained in 25.0 mL of butane? The density of butane is 0.6011 g mL-1 and the molar mass is 58.12 g mol-1.

Identify the formula for sulfurous acid.

Determine the mass percent (to the hundredths place)of H in sodium bicarbonate (NaHCO3).

How many molecules are in 114.86 g of vitamin C, C6H8O6?

What mass of ethane, CH6, contains the same number of molecules as 3.00 g of trichlorofluoromethane, CCl3F?

What is the mass of 8.50 × 1022 molecules of NH3?

Identify the formula for the compound formed between potassium and sulfur.

Combustion analysis of an unknown hydrocarbon produced the following results: C 52.14%, H 13.13%, O 34.73%. Determine the empirical formula.

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Chemical Reactions and Stoichiometry

Gases

Thermochemistry

The Quantum-Mechanical Model of the Atom

Periodic Properties of the Elements

Chemical Bonding I: Lewis Theory

Chemical Bonding Ii: Molecular Shapes, Valence Bond Theory, and Molecular Orbital Theory

Liquids, Solids, and Intermolecular Forces

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Gibbs Energy and Thermodynamics

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Filters

How many anions are there in 2.50 g of MgBr₂?

Combustion analysis of an unknown compound containing only carbon and hydrogen produced 0.2845 g of CO₂ and 0.1451 g of H₂O. What is the empirical formula of the compound?

Combustion analysis of 63.8 mg of a C, H, and O-containing compound produced 145.0 mg of CO₂ and 59.38 mg of H₂O. What is the empirical formula for the compound?

Calculate the number of carbon atoms in 76.91 g of benzoic acid, C₆H₅COOH.

Determine the molecular formula of a compound that is 49.48% carbon, 5.19% hydrogen, 28.85% nitrogen, and 16.48% oxygen. The molecular weight is 194.19 g mol^-1.

What is the mass of 9.44 × 10²⁴ molecules of NO₂? The molar mass of NO₂ is 46.01 g mol^-1.

How many molecules of butane are contained in 25.0 mL of butane? The density of butane is 0.6011 g mL^-1 and the molar mass is 58.12 g mol^-1.

Determine the mass percent (to the hundredths place)of H in sodium bicarbonate (NaHCO₃).

How many molecules are in 114.86 g of vitamin C, C₆H₈O₆?

What mass of ethane, CH₆, contains the same number of molecules as 3.00 g of trichlorofluoromethane, CCl₃F?

What is the mass of 8.50 × 10²² molecules of NH₃?