Question

when bases dissolve in water they release hydroxide ions. true false a reactant is a pure substance that is formed in a chemical change. true false neutralization involves mixing acids and salts together. true false the law of conservation of mass states that matter is neither created nor destroyed in a reaction.

Explanation:

1. Bases are defined as substances that release hydroxide ions ($OH^-$) when dissolved in water, so the first statement is true.
2. A reactant is a substance that participates in a chemical - change and is consumed, while a product is a pure substance that is formed in a chemical change. So the second statement is false.
3. Neutralization is the reaction between an acid and a base, not an acid and a salt. So the third statement is false.
4. The law of conservation of mass indeed states that matter is neither created nor destroyed in a chemical reaction.

Answer:

1. True
2. False
3. False
4. True