Calculate the mass of 10% hydrochloric acid required to dissolve 3.68 dolomite.

Given:

m (CaMg (CO3) 2) = 3.68 g

To find:

m (HCl) -?

Decision:

4HCl + CaMg (CO3) 2 = CaCl2 + MgCl2 + 2CO2 + 2H2O, – we solve the problem based on the composed reaction equation:

1) Find the amount of dolomite that has reacted:

n (CaMg (CO3) 2) = m: M = 3.68 g: 184 g / mol = 0.02 mol

2) We compose a logical expression:

if 1 mol of CaMg (CO3) 2 requires 4 mol of HCl,

then 0.02 mol CaMg (CO3) 2 will require x mol HCl,

then x = 0.08 mol.

3) Find the mass of hydrochloric acid that has reacted:

m (HCl) = n * M = 0.08 mol * 36.5 g / mol = 2.92 g.

Answer: m (HCl) = 2.92 g.