Deck 10: Quantity Relationships in Chemical Reactions

Question 1

Consider the hypothetical reaction A + 2 B $\rightarrow$ AB₂.If 2 moles of A and 5 moles of B are placed in a container an allowed to react,how many moles of AB₂ will be formed and how many moles of which reactant will remain unreacted?

A)2 moles of AB₂ will form and 3 moles of B will remain unreacted.
B)2 moles of AB₂ will form and 1 mole of B will remain unreacted.
C)5 moles of AB₂ will form and 3 moles of B will remain unreacted.
D)4 moles of AB₂ will form and 1 mole of B will remain unreacted.
E)5/2 (2.5)moles of AB₂ will form and nothing will remain unreacted.

Answer 1

2 moles of AB₂ will form and 1 mole of B will remain unreacted.

Question 2

Consider the conversion diagram given below. At which point(s)in the diagram is a molar mass needed?

A)A and B
B)B and E
C)A and D
D)D and E
E)C only

Answer 2

A and D

Question 3

How many moles of oxygen are consumed in the complete combustion of 1.60 moles of benzene,C₆H₆?

A)6.00 mol
B)12.0 mol
C)15.0 mol
D)18.0 mol
E)24.0 mol

Answer 3

12.0 mol

Question 4

In reacting aluminum carbonate with hydrochloric acid according to the equation Al₂(CO₃)₃ + 6 HCl $\rightarrow$ 2 AlCl₃ + 3 H₂O + 3 CO₂,57.6 mg of carbon dioxide was formed.What mass of aluminum carbonate reacted to form this amount of carbon dioxide?

A)10.8 mg
B)32.5 mg
C)102 mg
D)306 mg
E)919 mg

Question 5

In the reaction P₄ + 5 O₂ $\rightarrow$ 2 P₂O₅,in order the convert from moles of any substance to moles of another substance as shown by the block diagram. What is the conversion factor needed?

A)molar mass of a reactant
B)molar mass of a product
C)mole ratio from the equation
D)Avogadro's number

Question 6

The reaction C₆H₆ + HNO₃ $\rightarrow$ C₆H₅NO₂ + H₂O has a 73.5 percent yield under certain conditions.If 12.75 g of C₆H₆ is used,how much C₆H₅NO₂ will be produced?

A)20.1 g
B)27.4 g
C)8.09 g
D)11.0 g
E)14.8 g

Question 7

Which of the following defines the percent yield for a reaction?

A)
B)
C)
D)

Question 8

How many moles of water are produced by burning 5.77 moles of C₄H₁₀?

A)1.15 mol
B)5.77 mol
C)23.1 mol
D)28.9 mol
E)37.5 mol

Question 9

Which of the following best describes a limiting reactant?

A)The reactant that limits the rate (or speed)of a chemical reaction.
B)The reactant that limits the position of equilibrium in a reversible chemical change.
C)The reactant that remains at the end of the reaction.
D)The reactant that can produce the greatest amount of product.
E)The reactant that is completely used up by a reaction.

Question 10

How many moles of bromine will react with 0.0500 mole of C₂H₂ in the reaction C₂H₄ + Br₂ $\rightarrow$ C₂H₄Br₂?

A)0.100 mol
B)0.186 mol
C)0.0250 mol
D)0.0500 mol
E)2.00 mol

Question 11

In the reaction CaCN₂ + 3 H₂O $\rightarrow$ CaCO₃ + 2 NH₃,how many kilograms of NH₃ will be produced when 25.0 kg of CaCN₂ react with excess water?

A)10.6 kg
B)12.9 kg
C)2.66 kg
D)5.31 kg
E)7.56 kg

Question 12

Barium chloride was used to precipitate silver chloride from a solution of silver nitrate.What mass of barium chloride had to react if 0.635 g of silver chloride formed?

A)0.437 g
B)0.461 g
C)0.874 g
D)0.923 g
E)1.85 g

Question 13

In the reaction 2 AgI + HgI₂ $\rightarrow$ Ag₂HgI₄,2.00 g of AgI and 3.50 g of HgI₂ were used.What is the limiting reactant?

A)AgI
B)HgI₂
C)Ag₂HgI₄
D)There is no limiting reactant.

Question 14

A chemical reaction resulted in 1.376 g of product,which represented a 78.5 percent yield for the reaction.What is the theoretical yield?

A)0.785 g
B)1.08 g
C)10.8 g
D)1.75 g
E)2.16 g

Question 15

In the complete combustion of C₃H₈O₃,how many moles of carbon dioxide are produced when 23.0 g of C₃H₈O₃ burns?

A)0.250 mol
B)0.750 mol
C)0.0833 mol
D)3.00 mol
E)33.0 mol

Question 16

Silver nitrate and magnesium chloride solutions are mixed.What is the Per expression that allows one to convert moles of silver nitrate to moles of magnesium chloride?

A)
B)
C)
D)

Question 17

PCl₅ can be produced by the reaction PCl₃ + Cl₂ $\rightarrow$ PCl₅.What mass of PCl₃ must be used to produce 127 g of PCl₅ if the percent yield is 84.8%?

A)71.1 g
B)83.8 g
C)98.8 g
D)108 g
E)150 g

Question 18

How many moles of C₆H₁₂O₆ are formed when 0.250 mole of CO₂ is consumed in the reaction 6 CO₂ + 6 H₂O $\rightarrow$ C₆H₁₂O₆ + 6 O₂?

A)1.50 mol
B)1.00 mol
C)0.250 mol
D)0.167 mol
E)0.0417 mol

Question 19

The reaction 2 Sb + 3 Cl₂ $\rightarrow$ 2 SbCl₃ has an 88.3% yield.If 4.07 g of SbCl₃ is desired,what mass of chlorine should be used?

A)2.15 g
B)0.957 g
C)1.68 g
D)1.90 g
E)3.00 g

Question 20

In the combustion of natural gas according to the equation CH₄ + 2 O₂ $\rightarrow$ CO₂ + 2 H₂O,how many grams of water are formed during the combustion of 0.264 mole of CH₄?

A)0.528 g
B)2.00 g
C)2.38 g
D)4.75 g
E)9.50 g

Question 21

When one mole of gaseous hydrogen peroxide,H₂O₂,is made from hydrogen and oxygen gases,the enthalpy change is -136 kJ.Which of the following correctly represents the thermochemical equation?
(i)H₂(g)+ O₂(g) $\rightarrow$ H₂O₂(g)+ 136 kJ
(ii)H₂(g)+ O₂(g)+ 136 kJ $\rightarrow$ H₂O₂(g)
(iii)H₂(g)+ O₂(g) $\rightarrow$ H₂O₂(g)?0?H = -136 kJ
(iv)H₂(g)+ O₂(g) $\rightarrow$ H₂O₂(g)?0?H = +136 kJ

A)i only
B)ii only
C)iii only
D)i and iii
E)ii and iv

Question 22

Ammonium sulfate can be made by the reaction H₂SO₄ + 2 NH₃ $\rightarrow$ (NH₄)₂SO₄.What quantity of ammonium sulfate will result from the reaction of 5.00 kg of ammonia and 20.0 kg of sulfuric acid?

A)13.5 kg
B)19.4 kg
C)25.0 kg
D)26.9 kg
E)38.8 kg

Question 23

Formation of two moles of hydrogen chloride gas from the gases hydrogen and chlorine is a reaction for which $\Delta$ H is -185 kJ.Which of the following statements is correct?
(i)The reaction is exothermic.
(ii)Enthalpy of the system decreases.
(iii)Heat is a "product".

A)All are correct
B)All are incorrect
C)i only
D)ii only
E)iii only

Question 24

How much energy is required to produce 1.00 kg of aluminum by the reaction 2 Al₂O₃(s)+ 3 C(s)+ 1.97 * 10³ kJ $\rightarrow$ 4 Al(s)+ 3 CO₂(g)?

A)5.50 * 10^-5 kJ
B)7.52 * 10^-2 kJ
C)2.70 *10³ kJ
D)7.30 * 10⁴ kJ
E)1.83 * 10⁴ kJ

Question 25

$\Delta$ H = +572 kJ for the decomposition of water by the reaction 2 H₂O( ) $\rightarrow$ 2 H₂(g)+ O₂(g).How many grams of water can be decomposed by 5.00 *10³ kJ of energy?

A)157 g
B)315 g
C)0.0629 g
D)2.57* 10⁷ g
E)5.15 * 10⁷ g

Question 26

The metabolism of glucose can be represented by the equation C₆H₁₂O₆(s)+ 6 O₂(g) $\rightarrow$ 6 CO₂(g)+ 6 H₂O(g) $\Delta$ H = -2.82 *10³ kJ.How many grams of glucose must be metabolized to produce 282 kJ of energy?

A)18.0 g
B)1.80 * 10² g
C)0.100 g
D)10.0 g
E)67.4 g

Question 27

Cu₂HgI₄ is prepared according to the equation 2 CuI + HgI₂ $\rightarrow$ Cu₂HgI₄.When 2.00 g of each reactant are used,which one is the limiting reactant?

A)Both reactants are limiting
B)This reaction has no limiting reactant
C)CuI
D)HgI₂
E)Cu₂HgI₄

Question 28

A typical diet provides about 2000 food Calories per day,or 2000 kilocalories.Calculate the equivalent number of joules.

A)8 J
B)8 *10³ J
C)8 * 10⁶ J
D)0.5 J
E)5 * 10⁵ J

Question 29

A typical candy bar contains 281 food Calories,which is 281 kcal.How many kilojoules are contained in one such candy bar?

A)1.18 * 10³ kJ
B)1.18 *10⁴ kJ
C)67.2 kJ
D)672 kJ
E)6.72 * 10⁴ kJ

Question 30

When 1.00 g of C₆H₁₂O₆(s)is formed during photosynthesis,15.67 kJ of the sun's energy is converted to chemical energy.What is the thermochemical equation for the photosynthesis of glucose?

A)6 CO₂(g)+ 6 H₂O(g) $\rightarrow$ C₆H₁₂O₆(s)+ 6 O₂(g)+ 15.67 kJ
B)CO₂(g)+ H₂O(g) $\rightarrow$ C₆H₁₂O₆(s)+ O₂(g)?0?H = 15.67 kJ
C)6 CO₂(g)+ 6 H₂O(g)+ 2.82 *10³ kJ $\rightarrow$ C₆H₁₂O₆(s)+ 6 O₂(g)
D)C₆H₁₂O₆(s)+ 6 O₂(g) $\rightarrow$ 6 CO₂(g)+ 6 H₂O(g)+ 2.82*10³ kJ
E)6 CO₂(g)+ 6 H₂O(g) $\rightarrow$ C₆H₁₂O₆(s)+ 6 O₂(g)?0?H = -2.82 * 10³ kJ

Question 31

If the reaction N₂ + 3 H₂ $\rightarrow$ 2 NH₃ is carried out using 1.40 g of N₂ and 0.400 g of H₂,what mass of excess reactant will remain?

A)0.200 g N₂
B)1.00 g N₂
C)0.100 g H₂
D)0.300 g H₂
E)Both reactants will be completely consumed

Question 32

The thermochemical equation describing the heat change in the decomposition of limestone,CaCO₃,is given by CaCO₃(s)+ 176 kJ $\rightarrow$ CaO(s)+ CO₂(g).What is the heat change that accompanies the decomposition of 25.0 g of limestone?

A)7.12 kJ
B)25.0 kJ
C)44.0 kJ
D)176 kJ
E)1.42 *10^-3 kJ

Question 33

Consider the following thermochemical equation: CaO(s)+ H₂O( ) $\rightarrow$ Ca(OH)₂(s) $\Delta$ H = -66.5 kJ Which of the following statements is/are correct?
(i)The reaction is exothermic
(ii)The reaction releases 66.5 kJ per gram of Ca(OH)₂(s)formed
(iii)Alternatively,the $\Delta$ H term could be added to the product side of the equation

A)i only
B)ii only
C)i and ii
D)i and iii
E)i,ii,and iii

Question 34

Convert 357 J to kcal.

A)1.49 kcal
B)1.49 * 10⁶ kcal
C)8.53 *10⁴ kcal
D)85.3 kcal
E)0.0853 kcal

Question 35

The decomposition of potassium chlorate is written as shown below.What energy change occurs when 12.3 g of KClO₃ decompose? 2 KClO₃(s)+ 89.6 kJ $\rightarrow$ 2 KCl(s)+ 3 O₂(g)

A)Release of 8.99 kJ
B)Absorption of 8.99 kJ
C)Release of 4.49 kJ
D)Absorption of 4.49 kJ
E)Release of 0.00112 kJ

Question 36

Aqueous HCl is added to an aqueous solution of NaOH at 25 °C and the result is shown in the figure below. Which of the following correctly characterizes this reaction?

A)The reaction is exothermic.
B)The $\Delta$ H for the reaction has a + sign.
C)Energy could be considered to be a reactant in the equation for the reaction.
D)The energy (enthalpy)of the products is greater than the reactants.
E)This reaction consumes energy.

Question 37

A chemist combines hydrochloric acid with a sodium hydroxide solution,transferring 5.75 kJ of heat.Express this in calories.

A)2.41* 10^-2 cal
B)2.41* 10¹ cal
C)2.41 *10⁴ cal
D)1.37 *10^-3 cal
E)1.37 * 10³ cal

Question 38

Calculate the mass of Na₂O that can be produced by the reaction of 4.00 g of sodium and 2.00 g of oxygen in the reaction 4 Na + O₂ $\rightarrow$ 2 Na₂O.

A)1.94 g
B)2.00 g
C)4.50 g
D)5.39 g
E)6.00 g

Question 39

When C₂H₅Cl(g)is burned in oxygen,chlorine gas is produced in addition to carbon dioxide and water vapor.5145 kJ of heat are released for every four moles of C₂H₅Cl(g)burned.Which of the following correctly represents the thermochemical equation?

A)4 C₂H₅Cl(g)+ 5145 kJ + 13 O₂(g) $\rightarrow$ 2 Cl₂(g)+ 8 CO₂(g)+ 10 H₂O(g)
B)4 C₂H₅Cl(g)+ 13 O₂(g)+ 5145 kJ $\rightarrow$ 2 Cl₂(g)+ 8 CO₂(g)+ 10 H₂O(g)
C)4 C₂H₅Cl(g)+ 13 O₂(g) $\rightarrow$ (5145 kJ) $\rightarrow$ 2 Cl₂(g)+ 8 CO₂(g)+ 10 H₂O(g)
D)4 C₂H₅Cl(g)+ 13 O₂(g) $\rightarrow$ 2 Cl₂(g)+ 8 CO₂(g)+ 10 H₂O(g)?0?H = +5145 kJ
E)4 C₂H₅Cl(g)+ 13 O₂(g) $\rightarrow$ 2 Cl₂(g)+ 8 CO₂(g)+ 10 H₂O(g)?0?H = -5145 kJ

Question 40

What is the theoretical yield of phosphorus triiodide when 4.50 g of phosphorus is combined with 45.0 g of iodine? The compound is made by the direct combination of the elements.

A)48.7 g
B)49.5 g
C)59.8 g
D)30.0 g
E)39.9 g