Question

Which of the following has smallest number of molecules?

• A. 0.1 mole of $C{O}_2$ gas
• B. 11.2 litres of $C{O}_2$ gas
• C. 22 gm of $C{O}_2$ gas
• D. 22.4$\times {10}^3$ ml of $C{O}_2$ gas

Answer 1

The correct option is A 0.1 mole of $C{O}_2$ gas

A) 0.1 mole of $C{O}_2$:
No. of molecules $=6.02\times {10}^{23}\times 0.1$ $=0.602\times {10}^{23}$
B) 11.2L of $C{O}_2$:
No. of molecules $=\frac{6.02\times {10}^{23}}{22.4}\times 11.2$ $=3.01\times {10}^{23}$
C) 22g of $C{O}_2$:
No. of molecules $=\frac{6.02\times {10}^{23}}{44}\times 22$ $=3.01\times {10}^{23}$
D) $22.4\times {10}^{3}ml$(22.4L) of $C{O}_2$: no. of molecules $=6.02\times {10}^{23}$
Therefore Option(A) is correct as it has smallest number of molecules.