Question

1. choose the best answer. when an ionic compound is dissolved in water it separates into separate ions, which is called ______

a dissociation
a gas bubble
a synthesis reaction
a precipitate

1. choose the best answer. which of the following equations represents a decomposition reaction?

$2no + o_2 \
ightarrow 2no_2$

$mgco_3 (s) \
ightarrow mgo (s) + co_2 (g)$

$8fe + s_8 \
ightarrow 8fes$

$2co (g) + o_2 (g) \
ightarrow 2co_2 (g)$

Explanation:

Step1: Analyze Question 13

Define dissociation: ionic compound splits into ions in water. Match with options.

Step2: Analyze Question 14

Define decomposition: 1 reactant → multiple products. Match with options.

Answer:

1. a. dissociation
2. $\text{MgCO}_3(s)

ightarrow \text{MgO}(s) + \text{CO}_2(g)$