Question

The number of oxygen atoms present in $50g$ of calcium carbonate is?

• A. $6.023\times {10}^{23}$
• B. $30.1\times {10}^{23}$
• C. $9.035\times {10}^{23}$
• D. $1.206\times {10}^{24}$

Answer 1

Answer: (C)

$9.035\times {10}^{23}$

M.wt of $CaC{O}_3=100$

number of moles of CaCO_3 present in 50gm =$\frac{50}{100}=0.5$

1 mole of $CaC{O}_3$ = 3 moles of $O_2$

0.5 moles of $CaC{O}_3$ has 1.5 moles of oxygen.

$1mole=6.022\ast {10}^{23}particles$

$\therefore$ 50g of $CaC{O}_3=1.5\ast (6.022\ast {10}^{23})=9.035\ast {10}^{23}$ oxygen atoms.