Answer to Question #21207 in Physical Chemistry for ekansh

Question

Q. 50g CaCO3 will react with ......g of 20% HCl by weight-
(i) 36.5 gm (ii)73 gm (iii)109.5 gm (iv)182.5 gm

Answer 1

Equation of the reaction between calcium carbonate and hydrochloric acid

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

The molar mass of CaCO₃ is 100 g/mol. Thus the amount of 50g of CaCO₃ is 0.5 mol.
One mol of calcium carbonate reacts with two mol of hydrochloric acid. Thus, 0.5 mol of CaCO₃ reacts with 1 mol of HCl.
The molar mass of HCl is 36.5 g/mol. The mass of 1 mol HCl is 36.5 g.
The concentration of HCl in the solution by weight is
w(HCl) = m(HCl) / m(solution)
Thus, the mass of the 20% solution of 36.5 g of HCl is
m(HCl solution) = m(HCl) / w(HCl) = 36.5 g / 0.2 = 182.5 g.

Answer: (iv) 182.5 g
50g CaCO3 will react with 182.5 g of 20% HCl by weight.