JEE Main · 2025 · 02 Apr 2025 · Shift 1 · Some Basic Concepts of Chemistry

CaCO X_{3} (s) + 2 HCl (aq) CaCl X_{2} (aq) + CO X_{2} (g) + H X_{2} O (l)

Consider the above reaction, what mass of

CaCl X_{2}

will be formed if 250 mL of 0.76 M HCl reacts with 1000 g of

CaCO X_{3}

?
(Given : Molar mass of Ca, C, O, H and Cl are 40, 12, 16, 1 and 35.5 g mol

^{- 1}

, respectively)

Answer: (C)

Solution

The calcium carbonate present is

1000/100 = 10

mol, while the acid supplies only

0.76 \times 0.250 = 0.19

mol. Since two moles of acid are needed for each mole of carbonate, the acid is the limiting reagent. Every two moles of HCl give one mole of

CaCl X_{2}

, so

0.19

mol acid yields

0.095

mol of the salt. With the molar mass of

CaCl X_{2}

equal to

40 + 2 \times 35.5 = 111 g mol^{- 1}

, the mass formed is

0.095 \times 111 = 10.545 g

JEE Main · 2025 · 02 Apr 2025 · Shift 1 · Single correct option