Question

Calculate the mass of cacl2 produced when chemical rxn was carried out by mixing 25 gm of pure calcium carbonate and 0.75 mole of pure hydrochloric acid

Answer 1

Answer:

CaCO3 + 2HCl -----> CaCl2 + H2O + CO2.

2.5g? g

Mass of CaCO3= 40+12+3(16)=52+ 48= 100.

Molar mass of CaCO3=100g.

Mass of CaCl2= 40 + 2(35.5)= 40+ 71= 111.

Molar mass of CaCl2=111g.

Mass of CaCO3 (g) Mass of CaCl2 (g)

For 100g of CaCO The mass of HCl is

1000

0.75×36.5

×25=0.684g.

1 mole of calcium carbonate reacts with 2 moles of HCl.

Hence, the mass of calcium carbonate that will react completely with 0.684 g of HCl is

2×36.5

100

×0.684=0.937g.

3

, 111g of CaCl_2$$ is formed.

let for 2.5g of CaCO

3

, x g of CaCl

2

is formed.

Thus, by cross multiplication,

x=111×2.5/100=2.775g=2.78g.