Question

What mass of hydrochloric acid is needed to decompose 50 g of limestone?

• A. $36.5g$
• B. 73 g
• C. 50 g
• D. 100g

Answer 1

Answer: (A)

$36.5g$

Answer 2

(1) : $\underset{100g}{CaCO_{3}} + \underset{2 \times 36.5 = 73g}{2HCl \rightarrow}CaCl_{2} + H_{2}O + CO_{2}$

100 g of $CaCO_{3}$requires 73 g of HCl

$\therefore$50 g of $CaCO_{3}$requires $\frac{73}{100} \times 50 = 36.5g$of HCl