This is my last problem and i don't know whether or not this is right. can someone me? < 3 < 3 < 3 (7th grade math)

You got the total number of pages correct, but the equation gets you 39 total pages. Instead of multiplying by 1/3, you multiply by 3 because 114+3 is 1/3 of the total pages. So:

(114+3) · 3 = p

351 = p

Hypothesis:

The amount of limestone that dissolves in the acid is directly proportional to the concentration of acid used.

Explanation:

Acids dissolve limestone according to the following general equation;

2HX(aq) + CaCO3(s) > CaX2(aq) + H2O (l) + CO2(g). Where HX represents any acid at all.

This dissolution process is a chemical reaction. It was experimentally observed that the amount of limestone that dissolved in acid depends on the concentration of acid. Various concentrations of acid were then prepared and a particular mass of limestone was dissolved in each concentration of acid. The amount of limestone dissolved in each case was carefully noted.

It was observed that as the concentration of acid increased, the amount of limestone dissolved increased also and vice versa, hence the hypothesis proposed above.