Which ions in a total ionic equation are called spectator ions? Why?

How do total and net ionic equations differ?

What must form in order for a double-displacement reaction to occur?

When will a displacement reaction not occur?

What is an activity series?

What are some of the characteristics of each of these five common chemical reactions? a. combustion, b. synthesis, c. decomposition, d. displacement, e. double-displacement.

The white paste that lifeguards rub on their nose to prevent sunburn contains zinc oxide, $ZnO(s)$, as an active ingredient. Zinc oxide is produced by burning zinc sulfide. $2 \mathrm{ZnS}(s)+3 \mathrm{O}_{2}(g) \longrightarrow 2 \mathrm{ZnO}(s)+2 \mathrm{SO}_{2}(g)$ a. What is the coefficient for sulfur dioxide? b. What is the subscript for oxygen gas? c. How many atoms of oxygen react? d. How many atoms of oxygen appear in the total number of sulfur dioxide molecules?

In balancing a chemical equation, why can you change coefficients, but not subscripts?

How does the process of balancing an equation illustrate the law of conservation of mass?

Translate the following chemical equation into a sentence: $\mathrm{CH}_{4}(g)+2 \mathrm{O}_{2}(g) \longrightarrow \mathrm{CO}_{2}(g)+2 \mathrm{H}_{2} \mathrm{O}(g)$

Evaporating ocean water leaves a mixture of salts. Is this a chemical change? Explain.

Calcium oxide, $CaO$, is an ingredient in cement mixes. When water is added, the mixture warms up and calcium hydroxide, $Ca(OH)_2$, forms. a. Is there any evidence of a chemical reaction? b. In the reaction above, how can you prove that a chemical reaction has taken place?

Write an unbalanced formula equation for each of the following. Include symbols for physical states in the equation. a. solid zinc sulfide + oxygen gas $\longrightarrow$ solid zinc oxide + sulfur dioxide gas, b. aqueous hydrochloric acid + solid magnesium hydroxide $\longrightarrow$ aqueous magnesium chloride + liquid water.

Write the symbol used in a chemical equation to represent each of the following: a. an aqueous solution, b. heated, c. a reversible reaction, d. a solid, e. at a temperature of $25^{\circ} \mathrm{C}$.