That would be exothermic. Exothermic reactions are processes that release energy, usually in the form of heat or light. Energy is released because the total energy of the products is less than the total energy of the reactants.
Independent variable would be salt since you can't change it in this experiment.
Answer:
five half lives
Explanation:
Half-life is the time required for a quantity to reduce to half of its initial value.
How many half lives it would take to reach 3.13% form 100% of it's initial concentration:
100% - 50% : First Half life
50% - 25%: Second Half life
25% - 12.5%: Third Half life
12.5% - 6.25%: Fourth Half life
6.25% - 3.125%: Fifth Half life
This means it would take five half lives to get to 3.125% (≈ 3.13%) of it's original concentration.