Q: Which of the following is the correct mole-to-mole conversion factor for the reaction $$2 \mathrm{C}_8\mathrm{H}_{18} (l) + 25 \mathrm{O}_2 (g) \rightarrow 16 \mathrm{CO}_2 (g) + 18 \mathrm{H}_2\mathrm{O} (g)$$ when converting moles of octane to moles of water?

$$\frac{18 \text{ mol } \mathrm{H}_2\mathrm{O}}{2 \text{ mol } \mathrm{C}_8\mathrm{H}_{18}}$$

Question 1

Which of the following best describes a combustion reaction?

Accepted Answer

A reaction in which a substance combines with oxygen to form one or more oxygen-containing compounds and emits heat.

Question 2

In the balanced chemical equation for photosynthesis, what is the correct stoichiometric relationship between carbon dioxide and glucose?

Accepted Answer

$$6 \mathrm{CO}_2 (g) + 6 \mathrm{H}_2\mathrm{O} (l) \rightarrow \mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 (aq) + 6 \mathrm{O}_2 (g)$$

Question 3

When balancing chemical equations, which quantity must always be the same on both sides of the equation?

Accepted Answer

Number of atoms of each kind

Question 4

Given the unbalanced equation for the combustion of methane: $$\mathrm{CH}_4 (g) + \mathrm{O}_2 (g) \rightarrow \mathrm{CO}_2 (g) + \mathrm{H}_2\mathrm{O} (g)$$, what is the correct balanced equation?

Accepted Answer

$$\mathrm{CH}_4 (g) + 2 \mathrm{O}_2 (g) \rightarrow \mathrm{CO}_2 (g) + 2 \mathrm{H}_2\mathrm{O} (g)$$

Question 5

If 22.0 moles of octane ($$\mathrm{C}_8\mathrm{H}_{18}) $$are combusted, how many moles of carbon dioxide ($$\mathrm{CO}_2) $$are produced according to the equation $$2 \mathrm{C}_8\mathrm{H}_{18} (l) + 25 \mathrm{O}_2 (g) \rightarrow 16 \mathrm{CO}_2 (g) + 18 \mathrm{H}_2\mathrm{O} (g)$$?

Accepted Answer

176 moles

Question 6

Which of the following is the correct mole-to-mole conversion factor for the reaction $$2 \mathrm{C}_8\mathrm{H}_{18} (l) + 25 \mathrm{O}_2 (g) \rightarrow 16 \mathrm{CO}_2 (g) + 18 \mathrm{H}_2\mathrm{O} (g)$$ when converting moles of octane to moles of water?

Accepted Answer

$$\frac{18 	ext{ mol } \mathrm{H}_2\mathrm{O}}{2 	ext{ mol } \mathrm{C}_8\mathrm{H}_{18}}$$

Question 7

A dose of milk of magnesia contains 3.26 g of $$\mathrm{Mg(OH)_2}. $$According to the reaction $$\mathrm{Mg(OH)_2} (s) + 2 \mathrm{HCl} (aq) \rightarrow 2 \mathrm{H}_2\mathrm{O} (l) + \mathrm{MgCl}_2 (aq)$$, what mass of $$\mathrm{HCl} (in $$grams) can be neutralized?

Accepted Answer

5.62 g

Question 8

In a reaction, you have 4 crusts, 10 cups of cheese, and 15 oz tomato sauce. According to the recipe $$1 	ext{ crust} + 5 	ext{ oz sauce} + 2 	ext{ cups cheese} ightarrow 1 	ext{ pizza}$$, what is the limiting reactant?

Accepted Answer

Tomato sauce

Question 9

Which statement about the limiting reactant in a chemical reaction is correct?

Accepted Answer

It is completely consumed and determines the maximum amount of product formed.

Question 10

If the theoretical yield of a reaction is 5.0 g and the actual yield is 3.5 g, what is the percent yield?

Accepted Answer

$$70\%$$

Question 11

For the reaction $$2 \mathrm{Mg} (s) + \mathrm{O}_2 (g) \rightarrow 2 \mathrm{MgO} (s)$$, if you start with 42.5 g of Mg and 33.8 g of $$\mathrm{O}_2$$, which is the limiting reactant?

Accepted Answer

$$\mathrm{Mg}$$

Question 12

In the reaction $$3 \mathrm{NO}_2 (g) + \mathrm{H}_2\mathrm{O} (l) \rightarrow 2 \mathrm{HNO}_3 (l) + \mathrm{NO} (g)$$, if 5 mol $$\mathrm{NO}_2$$ and 1 mol $$\mathrm{H}_2\mathrm{O}$$ are combined and react completely, how many moles of $$\mathrm{NO}_2$$ remain after the reaction?

Accepted Answer

2 mol $$\mathrm{NO}_2$$

Question 13

Which of the following is a correct balanced equation for the reaction between sodium metal and chlorine gas?

Accepted Answer

$$2 \mathrm{Na} (s) + \mathrm{Cl}_2 (g) \rightarrow 2 \mathrm{NaCl} (s)$$

Question 14

Which of the following reactions represents the combustion of ethanol ($$\mathrm{C}_2\mathrm{H}_5\mathrm{OH}$$)?

Accepted Answer

$$\mathrm{C}_2\mathrm{H}_5\mathrm{OH} (l) + 3 \mathrm{O}_2 (g) \rightarrow 2 \mathrm{CO}_2 (g) + 3 \mathrm{H}_2\mathrm{O} (g)$$

Question 15

Which of the following is true about excess reactants in a chemical reaction?

Accepted Answer

They are not completely consumed and remain after the reaction is complete.

Question 16

In the reaction $$2 \mathrm{Fe} (s) + 3 \mathrm{Cl}_2 (g) \rightarrow 2 \mathrm{FeCl}_3 (s)$$, how many moles of $$\mathrm{FeCl}_3$$ are produced from 4 moles of $$\mathrm{Fe}$$ and 6 moles of $$\mathrm{Cl}_2$$?

Accepted Answer

4 moles

Question 17

Which of the following equations correctly represents the reaction of an alkali metal (M) with water?

Accepted Answer

$$2 \mathrm{M} (s) + 2 \mathrm{H}_2\mathrm{O} (l) \rightarrow 2 \mathrm{M}^+ (aq) + 2 \mathrm{OH}^- (aq) + \mathrm{H}_2 (g)$$

Chemical Reactions and Chemical Quantities: Study Notes

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