Question

Which of the following contains the largest number of molecules?

• A. 0.2 mole of $H_2$
• B. 8.0 g of $H_2$
• C. 17 g of $H_{2}O$
• D. 6.0 g of $C{O}_2$

Answer 1

The correct option is B 8.0 g of $H_2$

A) No. of molecules in 0.2 moles of $H_2$ $=6.02\times {10}^{23}\times 0.2$ $=1.204\times {10}^{23}$

B) No. of molecules in 8g of $H_2$ $=\frac{6.02\times {10}^{23}\times 8}{2}$ $=24.08\times {10}^{23}$

C) No. of molecules in 17g of $H_{2}O$ $=\frac{6.02\times {10}^{23}\times 17}{18}$ $=5.6\times {10}^{23}$

D) No. of molecules in 6g of $C{O}_2$ $=\frac{6.02\times {10}^{23}\times 6}{44}$ $=0.820\times {10}^{23}$

Therefore, 8.0 g of $H_2$ has highest no. of molecules.
Option B is correct.