CBSE Class 11-science Answered

Now, according to the definition of molarity, the no. of moles are calculated for 1000 ml or 1 litre of the solution.

1000 ml of 0.75 M HCl contains HCl = 0.75 mol

So, 25 ml of 0.75 M HCl will contain HCl = 0.75x25/1000 = 0.01875 mol

2 mol of HCl reacts with = 1 mol of CaCO₃

So, 0.01875 mol of HCl will react with = 1x0.01875/2 = 0.009375 mol

Molar mass of CaCO₃ = 100 g

Hence, the mass of 0.009375 mol of CaCO₃ = no. of moles x molar mass

                                                               = 0.009375 x 100 = 0.9375 g