Question 1

If the theoretical yield for a reaction is 54.9 g, and 51.3 g of product are actually obtained, the percent yield is:

Accepted Answer

A) 0.934% 
B) 93.4% 
C) 107% 
D) 3.60% 
E) not enough information given 
A) 0.934% 
B) 93.4% 
C) 107% 
D) 3.60% 
E) not enough information given

Question 2

A can of soda has 1.50 x 102 Calories.Convert this energy to units of joules.

Accepted Answer

A) 628 J 
B) 6280 J 
C) 35.9 J 
D) 3.59 x 104 J 
E) 6.28 x 105 J 
A) 628 J 
B) 6280 J 
C) 35.9 J 
D) 3.59 x 104 J 
E) 6.28 x 105 J

Question 3

The coefficients of a balanced equation can be understood to represent either relative numbers of molecules or moles.

Accepted Answer

A) True 
 B)False

Question 4

When sulfur dioxide is formed from its elements, 296.8 kJ of energy is released.Convert this energy to units of calories.

Accepted Answer

A) 70.94 cal 
B) 7.094 x 104 cal 
C) 0.2968 cal 
D) 1.242 x 103 cal 
E) 1.242 x 106 cal 
A) 70.94 cal 
B) 7.094 x 104 cal 
C) 0.2968 cal 
D) 1.242 x 103 cal 
E) 1.242 x 106 cal

Question 5

Which of the following processes is exothermic?

Accepted Answer

A) boiling water to make tea 
B) cooking an egg 
C) heating food in a microwave oven 
D) an acid and base reacting together, and causing the solution to become warm 
E) water in a swimming pool getting warmer in the sun 
A) boiling water to make tea 
B) cooking an egg 
C) heating food in a microwave oven 
D) an acid and base reacting together, and causing the solution to become warm 
E) water in a swimming pool getting warmer in the sun

Question 6

When calculating the percent yield for a reaction, the only information necessary is the mass of each reactant.

Accepted Answer

A) True 
 B)False

Question 7

Iron metal reacts with chlorine gas according to the following equation: 2Fe(s) + 3Cl2(g) $\rightarrow$2FeCl3(s) If 25.6 g each of iron and chlorine are combined, how much FeCl3 should form?

Accepted Answer

A) 74.3 g 
B) 113 g 
C) 39.0 g 
D) 49.5 g 
E) 26.0 g 
A) 74.3 g 
B) 113 g 
C) 39.0 g 
D) 49.5 g 
E) 26.0 g

Question 8

Phosphine, PH3, a reactive and poisonous compound, reacts with oxygen as follows: 4PH3(g) + 8O2(g) $\rightarrow$P4O10(s) + 6H2O(g) If 9.2 moles of phosphine react with sufficient oxygen, how many moles of P4O10 should form?

Accepted Answer

A) 4.0 moles 
B) 9.2 moles 
C) 37 moles 
D) 2.3 moles 
E) 6.0 moles 
A) 4.0 moles 
B) 9.2 moles 
C) 37 moles 
D) 2.3 moles 
E) 6.0 moles

Question 9

Which of the following processes is endothermic?

Accepted Answer

A) burning gasoline in an internal combustion engine 
B) evaporation of perspiration on your skin 
C) burning wood in a fireplace 
D) condensing steam on a mirror 
E) hot coffee cooling down as it sits on the table 
A) burning gasoline in an internal combustion engine 
B) evaporation of perspiration on your skin 
C) burning wood in a fireplace 
D) condensing steam on a mirror 
E) hot coffee cooling down as it sits on the table

Question 10

A 5.00 g sample of a brownie was burned in a bomb calorimeter containing 2025 g of water.The temperature of the water increased from 23.50 $\degree$C to 33.47 $\degree$C.How much heat, in joules, did the brownie release when it burned? [Cwater = 4.184 J/(g $\degree$C)]

Accepted Answer

A) 1.99 x 105 J 
B) 2.80 x 105 J 
C) 4.92 x 102 J 
D) 8.45 x 104 J 
E) 7.00 x 102 J 
A) 1.99 x 105 J 
B) 2.80 x 105 J 
C) 4.92 x 102 J 
D) 8.45 x 104 J 
E) 7.00 x 102 J

Question 11

Aluminum metal reacts with sulfuric acid according to the following equation: 2Al(s) + 3H2SO4(aq) $\rightarrow$Al2(SO4)3(s) + 3H2(g) If 12.9 g of aluminum reacts with excess sulfuric acid, and 62.4 g of Al2(SO4)3 are collected, what is the percent yield of Al2(SO4)3?

Accepted Answer

A) 81.8% 
B) 49.5% 
C) 76.3% 
D) 131% 
E) not enough information given 
A) 81.8% 
B) 49.5% 
C) 76.3% 
D) 131% 
E) not enough information given

Question 12

A calorie used by nutritionists, 1 Calorie, is equal to 1000 cal or 1 kcal used by chemists.

Accepted Answer

A) True 
 B)False

Question 13

Which of the following is the best (simplest) balanced equation to represent the chemical reaction shown in the figure on any scale?

Accepted Answer

A) 16H + 10O$\rightarrow$ 16H + 10O 
B) 16H + 10O $\rightarrow$8H2O + O2  
C) 8H2 + 5O2 $\rightarrow$8H2O + O2  
D) 2H2 + O2 $\rightarrow$2H2O 
E) 4H2 + 2O2 $\rightarrow$4H2O 
A) 16H + 10O$\rightarrow$ 16H + 10O 
B) 16H + 10O $\rightarrow$8H2O + O2  
C) 8H2 + 5O2 $\rightarrow$8H2O + O2  
D) 2H2 + O2 $\rightarrow$2H2O 
E) 4H2 + 2O2 $\rightarrow$4H2O

Question 14

Consider the reaction N2(g) + 2O2(g) $\rightarrow$2NO2(g).The molecular image represents a mixture of N2(g) and O2(g) just before reaction occurs.What is the limiting reactant, and how much of the excess reactant remains after the reaction is complete? The image contains 3 N2 molecules and 9 O2 molecules.

Accepted Answer

A) N2(g), 6 O2(g) 
B) O2(g), 1 N2(g) 
C) N2(g), 3 O2(g) 
D) O2(g), 2 N2(g) 
E) N2(g), 7 O2(g) 
A) N2(g), 6 O2(g) 
B) O2(g), 1 N2(g) 
C) N2(g), 3 O2(g) 
D) O2(g), 2 N2(g) 
E) N2(g), 7 O2(g)

Question 15

A 43 g serving of a chocolate candy has 2.10 x 102 Calories.Convert this energy to units of joules.

Accepted Answer

A) 879 J 
B) 8.79 x 105 J 
C) 50.2 J 
D) 5.02 x 104 J 
E) 8.79 x 103 J 
A) 879 J 
B) 8.79 x 105 J 
C) 50.2 J 
D) 5.02 x 104 J 
E) 8.79 x 103 J

Question 16

When fats or other foods are burned in a bomb calorimeter, the calorimeter absorbs heat, so the reaction is endothermic.

Accepted Answer

A) True 
 B)False

Question 17

When carbon dioxide is formed from its elements, 393.5 kJ of energy is released.Convert this energy to units of calories.

Accepted Answer

A) 9.405 x 104 cal 
B) 94.05 cal 
C) 0.3935 cal 
D) 1.646 x 103 cal 
E) 1.646 x 106 cal 
A) 9.405 x 104 cal 
B) 94.05 cal 
C) 0.3935 cal 
D) 1.646 x 103 cal 
E) 1.646 x 106 cal

Question 18

An energy input of 227 kJ is required to form acetylene from its elements.Convert this energy to units of calories.

Accepted Answer

A) 9.50 x 102 cal 
B) 9.50 x 105 cal 
C) 0.227 cal 
D) 54.3 cal 
E) 5.43 x 104 cal 
A) 9.50 x 102 cal 
B) 9.50 x 105 cal 
C) 0.227 cal 
D) 54.3 cal 
E) 5.43 x 104 cal

Question 19

The q value for the following reaction is 178.0 kJ for every mole of CaCO3 that reacts: CaCO3(s) $\rightarrow$   CaO(s) + CO2(g) How much heat would be required to decompose 4.00 mol CaCO3(s), and is the reaction endothermic or exothermic?

Accepted Answer

A) 712 kJ; exothermic 
B) 712 kJ; endothermic 
C) 178 kJ; exothermic 
D) 44.5 kJ; endothermic 
E) 44.5 kJ; exothermic 
A) 712 kJ; exothermic 
B) 712 kJ; endothermic 
C) 178 kJ; exothermic 
D) 44.5 kJ; endothermic 
E) 44.5 kJ; exothermic

Question 20

Which of the following is the best (simplest) balanced equation to represent the chemical reaction shown in the figure on any scale?

Accepted Answer

A) 4A + 8B $\rightarrow$12AB 
B) 2A2 + 4B2 $\rightarrow$4A2B 
C) 2A2 + 4B2 $\rightarrow$4AB2  
D) A2 + B2$\rightarrow$AB2  
E) A2 + 2B2 $\rightarrow$2AB2  
A) 4A + 8B $\rightarrow$12AB 
B) 2A2 + 4B2 $\rightarrow$4A2B 
C) 2A2 + 4B2 $\rightarrow$4AB2  
D) A2 + B2$\rightarrow$AB2  
E) A2 + 2B2 $\rightarrow$2AB2

If the theoretical yield for a reaction is 54.9 g, and 51.3 g of product are actually obtained, the percent yield is:

A can of soda has 1.50 x 10²Calories.Convert this energy to units of joules.

The coefficients of a balanced equation can be understood to represent either relative numbers of molecules or moles.

When sulfur dioxide is formed from its elements, 296.8 kJ of energy is released.Convert this energy to units of calories.

Which of the following processes is exothermic?

When calculating the percent yield for a reaction, the only information necessary is the mass of each reactant.

Iron metal reacts with chlorine gas according to the following equation: 2Fe(s) + 3Cl₂(g) $\rightarrow$ 2FeCl₃(s) If 25.6 g each of iron and chlorine are combined, how much FeCl₃ should form?

Phosphine, PH₃, a reactive and poisonous compound, reacts with oxygen as follows: 4PH₃(g) + 8O₂(g) $\rightarrow$ P₄O₁₀(s) + 6H₂O(g) If 9.2 moles of phosphine react with sufficient oxygen, how many moles of P₄O₁₀ should form?

Which of the following processes is endothermic?

A 5.00 g sample of a brownie was burned in a bomb calorimeter containing 2025 g of water.The temperature of the water increased from 23.50 $\degree$ C to 33.47 $\degree$ C.How much heat, in joules, did the brownie release when it burned? [C_water = 4.184 J/(g $\degree$ C)]

Aluminum metal reacts with sulfuric acid according to the following equation: 2Al(s) + 3H₂SO₄(aq) $\rightarrow$ Al₂(SO₄)₃(s) + 3H₂(g) If 12.9 g of aluminum reacts with excess sulfuric acid, and 62.4 g of Al₂(SO₄)₃ are collected, what is the percent yield of Al₂(SO₄)₃?

A calorie used by nutritionists, 1 Calorie, is equal to 1000 cal or 1 kcal used by chemists.

Which of the following is the best (simplest) balanced equation to represent the chemical reaction shown in the figure on any scale?

A 43 g serving of a chocolate candy has 2.10 x 10²Calories.Convert this energy to units of joules.

When fats or other foods are burned in a bomb calorimeter, the calorimeter absorbs heat, so the reaction is endothermic.

When carbon dioxide is formed from its elements, 393.5 kJ of energy is released.Convert this energy to units of calories.

An energy input of 227 kJ is required to form acetylene from its elements.Convert this energy to units of calories.

The q value for the following reaction is 178.0 kJ for every mole of CaCO₃ that reacts: CaCO₃(s) $\rightarrow$ CaO(s) + CO₂(g) How much heat would be required to decompose 4.00 mol CaCO₃(s), and is the reaction endothermic or exothermic?

Which of the following is the best (simplest) balanced equation to represent the chemical reaction shown in the figure on any scale?

Matter and Energy

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Chemical Compounds

Chemical Composition

Chemical Reactions and Equations

Electron Structure of the Atom

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Solutions

Reaction Rates and Chemical Equilibrium

Acids and Bases

Oxidation-Reduction Reactions

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Exam 6: Quantities in Chemical Reactions

If the theoretical yield for a reaction is 54.9 g, and 51.3 g of product are actually obtained, the percent yield is:

A can of soda has 1.50 x 102 Calories.Convert this energy to units of joules.

The coefficients of a balanced equation can be understood to represent either relative numbers of molecules or moles.

When sulfur dioxide is formed from its elements, 296.8 kJ of energy is released.Convert this energy to units of calories.

Which of the following processes is exothermic?

When calculating the percent yield for a reaction, the only information necessary is the mass of each reactant.

Iron metal reacts with chlorine gas according to the following equation: 2Fe(s) + 3Cl2(g) →\rightarrow→ 2FeCl3(s) If 25.6 g each of iron and chlorine are combined, how much FeCl3 should form?

Phosphine, PH3, a reactive and poisonous compound, reacts with oxygen as follows: 4PH3(g) + 8O2(g) →\rightarrow→ P4O10(s) + 6H2O(g) If 9.2 moles of phosphine react with sufficient oxygen, how many moles of P4O10 should form?

Which of the following processes is endothermic?

A 5.00 g sample of a brownie was burned in a bomb calorimeter containing 2025 g of water.The temperature of the water increased from 23.50 °\degree° C to 33.47 °\degree° C.How much heat, in joules, did the brownie release when it burned? [Cwater = 4.184 J/(g °\degree° C)]

Aluminum metal reacts with sulfuric acid according to the following equation: 2Al(s) + 3H2SO4(aq) →\rightarrow→ Al2(SO4)3(s) + 3H2(g) If 12.9 g of aluminum reacts with excess sulfuric acid, and 62.4 g of Al2(SO4)3 are collected, what is the percent yield of Al2(SO4)3?

A calorie used by nutritionists, 1 Calorie, is equal to 1000 cal or 1 kcal used by chemists.

Which of the following is the best (simplest) balanced equation to represent the chemical reaction shown in the figure on any scale?

A 43 g serving of a chocolate candy has 2.10 x 102 Calories.Convert this energy to units of joules.

When fats or other foods are burned in a bomb calorimeter, the calorimeter absorbs heat, so the reaction is endothermic.

When carbon dioxide is formed from its elements, 393.5 kJ of energy is released.Convert this energy to units of calories.

An energy input of 227 kJ is required to form acetylene from its elements.Convert this energy to units of calories.

The q value for the following reaction is 178.0 kJ for every mole of CaCO3 that reacts: CaCO3(s) →\rightarrow→ CaO(s) + CO2(g) How much heat would be required to decompose 4.00 mol CaCO3(s), and is the reaction endothermic or exothermic?

Which of the following is the best (simplest) balanced equation to represent the chemical reaction shown in the figure on any scale?

Matter and Energy

Atoms, Ions, and the Periodic Table

Chemical Compounds

Chemical Composition

Chemical Reactions and Equations

Electron Structure of the Atom

Chemical Bonding

The Gaseous State

The Liquid and Solid States

Solutions

Reaction Rates and Chemical Equilibrium

Acids and Bases

Oxidation-Reduction Reactions

Nuclear Chemistry

Organic Chemistry

Biochemistry

Filters

A can of soda has 1.50 x 10²Calories.Convert this energy to units of joules.

Iron metal reacts with chlorine gas according to the following equation: 2Fe(s) + 3Cl₂(g) $\rightarrow$ 2FeCl₃(s) If 25.6 g each of iron and chlorine are combined, how much FeCl₃ should form?

Phosphine, PH₃, a reactive and poisonous compound, reacts with oxygen as follows: 4PH₃(g) + 8O₂(g) $\rightarrow$ P₄O₁₀(s) + 6H₂O(g) If 9.2 moles of phosphine react with sufficient oxygen, how many moles of P₄O₁₀ should form?

A 5.00 g sample of a brownie was burned in a bomb calorimeter containing 2025 g of water.The temperature of the water increased from 23.50 $\degree$ C to 33.47 $\degree$ C.How much heat, in joules, did the brownie release when it burned? [C_water = 4.184 J/(g $\degree$ C)]

Aluminum metal reacts with sulfuric acid according to the following equation: 2Al(s) + 3H₂SO₄(aq) $\rightarrow$ Al₂(SO₄)₃(s) + 3H₂(g) If 12.9 g of aluminum reacts with excess sulfuric acid, and 62.4 g of Al₂(SO₄)₃ are collected, what is the percent yield of Al₂(SO₄)₃?

A 43 g serving of a chocolate candy has 2.10 x 10²Calories.Convert this energy to units of joules.

The q value for the following reaction is 178.0 kJ for every mole of CaCO₃ that reacts: CaCO₃(s) $\rightarrow$ CaO(s) + CO₂(g) How much heat would be required to decompose 4.00 mol CaCO₃(s), and is the reaction endothermic or exothermic?