Question 1

What is the theoretical yield of PI3 from the reaction of 27.0 g of P and 68.0 g of I2?
2P(s)+ 3I2(s)$\rarr$ 2PI3(s)

Accepted Answer

Question 2

Calculate the percent composition by mass of sodium in Na2CO3.

Accepted Answer

Question 3

Balance the following chemical equation:
C4H10 + O2 $\rarr$CO2 + H2O

Accepted Answer

2C₄H₁₀ + 13 O

Question 4

When a 0.952 g sample of an organic compound containing C, H, and O is burned completely in oxygen, 1.35 g of CO2 and 0.826 g of H2O are produced. What is the empirical formula of the compound?

Accepted Answer

Question 5

How many moles of Cl atoms are there in 65.2 g CHCl3?

Accepted Answer

A) 0.548 mol 
B) 1.09 mol 
C) 3.3 * 1023 mol 
D) 1.64 mol 
E) 3.0 mol 
A) 0.548 mol 
B) 1.09 mol 
C) 3.3 * 1023 mol 
D) 1.64 mol 
E) 3.0 mol

Question 6

How many moles of O atoms are in 25.7 g of CaSO4?

Accepted Answer

A) 0.189 mol 
B) 0.755 mol 
C) 4.00 mol 
D) 1.14 * 1023 mol 
E) 4.55 * 1023 mol 
A) 0.189 mol 
B) 0.755 mol 
C) 4.00 mol 
D) 1.14 * 1023 mol 
E) 4.55 * 1023 mol

Question 7

Calculate the molecular mass of menthol, C10H20O.

Accepted Answer

A) 156 amu 
B) 140 amu 
C) 29 amu 
D) 146 amu 
E) 136 amu 
A) 156 amu 
B) 140 amu 
C) 29 amu 
D) 146 amu 
E) 136 amu

Question 8

One mole of iron

Accepted Answer

A) is heavier than one mole of lead (Pb). 
B) is 77.0 g of iron. 
C) is 26.0 g of iron. 
D) weighs the same as one mole of lead. 
E) None of the above. 
A) is heavier than one mole of lead (Pb). 
B) is 77.0 g of iron. 
C) is 26.0 g of iron. 
D) weighs the same as one mole of lead. 
E) None of the above.

Question 9

What is the mass of 7.80 * 1018 carbon atoms?

Accepted Answer

A) 1.30 * 10-5 g 
B) 6.43 * 103 g 
C) 7.80 * 1018 g 
D) 1.56 * 10-4 g 
E) 12.01 g 
A) 1.30 * 10-5 g 
B) 6.43 * 103 g 
C) 7.80 * 1018 g 
D) 1.56 * 10-4 g 
E) 12.01 g

Question 10

What is the average mass, in grams, of one potassium atom?

Accepted Answer

A) 5.14 * 10-23 g 
B) 6.49 * 10-23 g 
C) 6.02 * 10-18 g 
D) 31.0 g 
E) 39.1 g 
A) 5.14 * 10-23 g 
B) 6.49 * 10-23 g 
C) 6.02 * 10-18 g 
D) 31.0 g 
E) 39.1 g

Question 11

How many sulfur atoms are there in 21.0 g of Al2S3?

Accepted Answer

A) 8.42 * 1022 atoms 
B) 2.53 * 1023 atoms 
C) 2.14 * 1023 atoms 
D) 6.02 * 1023 atoms 
E) 6.30 * 1026 atoms 
A) 8.42 * 1022 atoms 
B) 2.53 * 1023 atoms 
C) 2.14 * 1023 atoms 
D) 6.02 * 1023 atoms 
E) 6.30 * 1026 atoms

Question 12

The mass of four moles of molecular bromine (Br2)is

Accepted Answer

A) 80 g. 
B) 320 g. 
C) 640 g. 
D) 140 g. 
E) 24 * 1023 g. 
A) 80 g. 
B) 320 g. 
C) 640 g. 
D) 140 g. 
E) 24 * 1023 g.

Question 13

Which one of the following does not represent 1.00 mol of the indicated substance?

Accepted Answer

A) 6.02 * 1023 C atoms 
B) 26.0 g Fe 
C) 12.01 g C 
D) 65.4 g Zn 
E) 6.02* 1023 Fe atoms 
A) 6.02 * 1023 C atoms 
B) 26.0 g Fe 
C) 12.01 g C 
D) 65.4 g Zn 
E) 6.02* 1023 Fe atoms

Question 14

The molecular formula of aspirin is C9H8O4. How many aspirin molecules are present in one 500-milligram tablet?

Accepted Answer

A) 2.77 molecules 
B) 2.77 * 10-3 molecules 
C) 1.67 * 1024 molecules 
D) 1.67 * 1021 molecules 
E) None of these is correct. 
A) 2.77 molecules 
B) 2.77 * 10-3 molecules 
C) 1.67 * 1024 molecules 
D) 1.67 * 1021 molecules 
E) None of these is correct.

Question 15

Refer to the (unbalanced)equation CS2 + CaO $\rarr$ CO2 + CaS. How many grams of CaS are produced if 53 g of CO2 are produced?

Accepted Answer

Question 16

What is the minimum mass of sulfur dioxide necessary to produce 200.g of sulfuric acid in the following reaction?
2SO2 + O2 + 2H2O $\rarr$2H2SO4

Accepted Answer

Question 17

A chemistry student determined the empirical formula for titanium sulfide (TixSy).To do so, she reacted titanium with excess sulfur in a crucible, and recorded the following data:   What is the empirical formula of titanium sulfide?

Accepted Answer

Question 18

If 0.274 moles of a substance weighs 62.5 g, what is the molar mass of the substance, in units of g/mol?

Accepted Answer

A) 2.28 * 102 g/mol 
B) 1.71 * 101 g/mol 
C) 4.38 * 10-3 g/mol 
D) 2.17 * 102 g/mol 
E) none of these 
A) 2.28 * 102 g/mol 
B) 1.71 * 101 g/mol 
C) 4.38 * 10-3 g/mol 
D) 2.17 * 102 g/mol 
E) none of these

Question 19

Phosphorus reacts with iodine as shown in the chemical reaction below.What is the percent yield of the reaction if 28.2 g PI3 is obtained from the reaction of 48.0 g of I2 with excess phosphorus?
2P(s)+ 3I2(s)$\rarr$2PI3(s)

Accepted Answer

Question 20

A method for producing pure copper metal involves the reaction of copper(I)sulfide with oxygen gas to give copper metal and sulfur dioxide. Suppose the yield of this reaction is 87%.What mass of a copper ore consisting of 46% copper(I)sulfide must be mined in order to produce 1.0 *103 kg (1.0 metric ton)of copper metal?

Accepted Answer

A) 1.4 * 103 kg 
B) 3.2 * 103 kg 
C) 1.3 * 103 kg 
D) 1.5 * 103 kg 
E) 8.0 * 103 kg 
A) 1.4 * 103 kg 
B) 3.2 * 103 kg 
C) 1.3 * 103 kg 
D) 1.5 * 103 kg 
E) 8.0 * 103 kg

Exam 3: Mass Relationships in Chemical Reactions

What is the theoretical yield of PI3 from the reaction of 27.0 g of P and 68.0 g of I2? 2P(s)+ 3I2(s) →\rarr→ 2PI3(s)

Calculate the percent composition by mass of sodium in Na2CO3.

Balance the following chemical equation: C4H10 + O2 →\rarr→ CO2 + H2O

When a 0.952 g sample of an organic compound containing C, H, and O is burned completely in oxygen, 1.35 g of CO2 and 0.826 g of H2O are produced. What is the empirical formula of the compound?

How many moles of Cl atoms are there in 65.2 g CHCl3?

How many moles of O atoms are in 25.7 g of CaSO4?

Calculate the molecular mass of menthol, C10H20O.

One mole of iron

What is the mass of 7.80 * 1018 carbon atoms?

What is the average mass, in grams, of one potassium atom?

How many sulfur atoms are there in 21.0 g of Al2S3?

The mass of four moles of molecular bromine (Br2)is

Which one of the following does not represent 1.00 mol of the indicated substance?

The molecular formula of aspirin is C9H8O4. How many aspirin molecules are present in one 500-milligram tablet?

Refer to the (unbalanced)equation CS2 + CaO →\rarr→ CO2 + CaS. How many grams of CaS are produced if 53 g of CO2 are produced?

What is the minimum mass of sulfur dioxide necessary to produce 200.g of sulfuric acid in the following reaction? 2SO2 + O2 + 2H2O →\rarr→ 2H2SO4

A chemistry student determined the empirical formula for titanium sulfide (TixSy).To do so, she reacted titanium with excess sulfur in a crucible, and recorded the following data: What is the empirical formula of titanium sulfide?

If 0.274 moles of a substance weighs 62.5 g, what is the molar mass of the substance, in units of g/mol?

Phosphorus reacts with iodine as shown in the chemical reaction below.What is the percent yield of the reaction if 28.2 g PI3 is obtained from the reaction of 48.0 g of I2 with excess phosphorus? 2P(s)+ 3I2(s) →\rarr→ 2PI3(s)

Chemistry: The Study of Change

Atoms, Molecules, and Ions

Reactions in Aqueous Solution

Gases

Thermo-Chemistry

Quantum Theory and the Electronic Structure of Atoms

Periodic Relationships Among the Elements

Chemical Bonding I: Basic Concepts

Chemical Bonding Ii: Molecular Geometry and Hybridization of Atomic Orbitals

Intermolecular Forces and Liquids and Solids

Physical Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acids and Bases

Acid-Base Equilibria and Solubility Equilibria

Chemistry in the Atmosphere

Entropy, Free Energy, and Equilibrium

Electrochemistry

Metallurgy and the Chemistry of Metals

Nonmetallic Elements and Their Compounds

Transition Metal Chemistry and Coordination Compounds

Nuclear Chemistry

Organic Chemistry

Synthetic and Natural Organic Polymers

Filters

What is the theoretical yield of PI₃ from the reaction of 27.0 g of P and 68.0 g of I₂? 2P(s)+ 3I₂(s) $\rarr$ 2PI₃(s)

Calculate the percent composition by mass of sodium in Na₂CO₃.

Balance the following chemical equation: C₄H₁₀ + O₂ $\rarr$ CO₂ + H₂O

When a 0.952 g sample of an organic compound containing C, H, and O is burned completely in oxygen, 1.35 g of CO₂ and 0.826 g of H₂O are produced. What is the empirical formula of the compound?

How many moles of Cl atoms are there in 65.2 g CHCl₃?

How many moles of O atoms are in 25.7 g of CaSO₄?

Calculate the molecular mass of menthol, C₁₀H₂₀O.

What is the mass of 7.80 * 10¹⁸ carbon atoms?

How many sulfur atoms are there in 21.0 g of Al₂S₃?

The mass of four moles of molecular bromine (Br₂)is

The molecular formula of aspirin is C₉H₈O₄. How many aspirin molecules are present in one 500-milligram tablet?

Refer to the (unbalanced)equation CS₂ + CaO $\rarr$ CO₂ + CaS. How many grams of CaS are produced if 53 g of CO₂ are produced?

What is the minimum mass of sulfur dioxide necessary to produce 200.g of sulfuric acid in the following reaction? 2SO₂ + O₂ + 2H₂O $\rarr$ 2H₂SO₄

A chemistry student determined the empirical formula for titanium sulfide (Ti_xS_y).To do so, she reacted titanium with excess sulfur in a crucible, and recorded the following data: What is the empirical formula of titanium sulfide?

Phosphorus reacts with iodine as shown in the chemical reaction below.What is the percent yield of the reaction if 28.2 g PI₃ is obtained from the reaction of 48.0 g of I₂ with excess phosphorus? 2P(s)+ 3I₂(s) $\rarr$ 2PI₃(s)