50ml of HCl sol. reacts completely w/ 10 gms of pure CaCO₃. The normality of HCl sol. is?

Question

Please explain the conversion, what is gms and the equation for obtaining the normality.

Answer 1

We start with a formula, of course, describing what happens: CaCO3 + 2HCl -> CaCl2 + H2O + CO2.  We need the number of moles of carbonate; the MW is 40+12+48 = 100.  Thus, we have 0.1 moles of carbonate, which will eat 0.2 moles of acid.  If 50 ml of HCl is 0.2 moles, 1000 ml would be 4 moles.  Which is what was to be determined.