Question

The pressure of a gas in a container is 10${}^{-11}$ pascal at 27${}^o$C. The number of molecules per unit volume of vessel will be

• A. $6\times {10}^{23}c{m}^{-3}$
• B. $2.68\times {10}^{19}c{m}^{-3}$
• C. $2.5\times {10}^{6}c{m}^{-3}$
• D. $2400c{m}^{-3}$

Answer 1

The correct option is D $2400c{m}^{-3}$

${10}^{5}Pa\equiv 6.023\times {10}^{23}$ (equivalence equation according to information given in question)
${10}^{-11}Pa\equiv 6.023\times {10}^7$
$22400cc\Rightarrow 6.023\times {10}^7$
$1cc\Rightarrow \frac{6.023\times {10}^7}{2400}=2400c{m}^{-3}$