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

$$\text{Na}_2\text{SO}_4(aq) + \text{BaCl}_2(aq) \rightarrow \text{BaSO}_4(s) + 2\text{NaCl}(aq)$$

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

$$\text{CH}_3\text{CH}_2\text{CH}_3$$

Question 1

A cold pack is activated by mixing ammonium nitrate with water. Which statement best describes the process occurring in the cold pack?

Accepted Answer

It is an endothermic reaction, absorbing heat and lowering the temperature.

Question 2

Which of the following is evidence that a chemical reaction has occurred?

Accepted Answer

Formation of a gas (bubbles) when CaCO$$_3$$ reacts with acid.

Question 3

Which law is illustrated by the fact that the number of atoms for each element is the same on both sides of a balanced chemical equation?

Accepted Answer

Law of Conservation of Matter

Question 4

Given the equation $$2	ext{H}_2(g) + 	ext{O}_2(g) ightarrow 2	ext{H}_2	ext{O}(g)$$, how many oxygen atoms are present in the reactants and products?

Accepted Answer

Reactants: 4, Products: 4

Question 5

Which of the following equations is balanced?

Accepted Answer

$$	ext{CH}_4(g) + 2	ext{O}_2(g) ightarrow 	ext{CO}_2(g) + 2	ext{H}_2	ext{O}(g)$$

Question 6

Which type of reaction is represented by $$	ext{S}(s) + 	ext{O}_2(g) ightarrow 	ext{SO}_2(g)$$?

Accepted Answer

Combination

Question 7

What is the correct classification for the reaction $$2	ext{HgO}(s) \xrightarrow{\Delta} 2	ext{Hg}(l) + 	ext{O}_2(g)$$?

Accepted Answer

Decomposition

Question 8

In the reaction $$	ext{Zn}(s) + 2	ext{HCl}(aq) ightarrow 	ext{ZnCl}_2(aq) + 	ext{H}_2(g)$$, which element is oxidized?

Accepted Answer

Zinc

Question 9

Which reaction is a double replacement reaction?

Accepted Answer

$$	ext{Na}_2	ext{SO}_4(aq) + 	ext{BaCl}_2(aq) ightarrow 	ext{BaSO}_4(s) + 2	ext{NaCl}(aq)$$

Question 10

Which of the following is a combustion reaction?

Accepted Answer

$$	ext{CH}_4(g) + 2	ext{O}_2(g) ightarrow 	ext{CO}_2(g) + 2	ext{H}_2	ext{O}(g) + 	ext{energy}$$

Question 11

In the reaction $$4	ext{Fe}(s) + 3	ext{O}_2(g) ightarrow 2	ext{Fe}_2	ext{O}_3(s)$$, what evidence indicates a chemical change?

Accepted Answer

Change in color as iron rusts

Question 12

Which statement best describes oxidation in an oxidation-reduction reaction?

Accepted Answer

Oxidation is the loss of electrons.

Question 13

Which of the following is a property typical of organic compounds?

Accepted Answer

Low density compared to water

Question 14

What elements are always found in organic compounds?

Accepted Answer

Carbon and hydrogen

Question 15

Which formula represents a hydrocarbon?

Accepted Answer

$$	ext{CH}_4$$

Question 16

What is the IUPAC name for a straight-chain alkane with six carbon atoms?

Accepted Answer

Hexane

Question 17

Which statement about cycloalkanes is correct?

Accepted Answer

Cycloalkanes are named by adding the prefix cyclo to the alkane name.

Question 18

What is the correct condensed structural formula for propane?

Accepted Answer

$$	ext{CH}_3	ext{CH}_2	ext{CH}_3$$

Question 19

Which of the following pairs are structural isomers?

Accepted Answer

Two compounds with the same molecular formula but different arrangements of atoms

Chemical Reactions and Quantities: Types, Equations, and Balancing

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