# Problem: A 1.130 g sample of limestone rock is pulverized and then treated with 30.00 mL of 1.035 M HCl solution. The excess acid then requires 11.56 mL of 1.010 M NaOH for neutralization.You may want to reference (Pages 149 - 153) Section 4.6 while completing this problem.Calculate the percent by mass of calcium carbonate in the rock, assuming that it is the only substance reacting with the HCl solution.

###### FREE Expert Solution

Reaction: CaCO3(aq) + HCl(aq) → CaCl2(aq) + H2CO3(aq)

H2CO3 decomposes to H2O(l) + CO2(g)

Reaction: CaCO3(aq) + 2 HCl(aq) → CaCl2(aq) + H2O(l) + CO2(g)

Calculate the moles HCl:

moles HCl = 0.03105 mol

Calculate the moles excess HCl:

HCl + NaOH → NaCl + H2O

moles excess acid = moles NaOH used for neutralization

moles excess HCl = 0.0116756 mol

###### Problem Details

A 1.130 g sample of limestone rock is pulverized and then treated with 30.00 mL of 1.035 M HCl solution. The excess acid then requires 11.56 mL of 1.010 M NaOH for neutralization.

You may want to reference (Pages 149 - 153) Section 4.6 while completing this problem.

Calculate the percent by mass of calcium carbonate in the rock, assuming that it is the only substance reacting with the HCl solution.