Question

How many moles of gas would you have if you had a volume of 38L under the pressure of 1432 mm Hg at standard temperature?

Answer 1

It is given in a question-

$$\begin{gathered} \mathrm{n}=? \\ \mathrm{standard}\mathrm{temperature} \\ \mathrm{T}=25°\mathrm{C}(25+273)=298\mathrm{K} \\ \mathrm{P}=1432\mathrm{mmHg}(1432/760)=1.88\mathrm{atm} \\ \mathrm{V}=38\mathrm{L} \end{gathered}$$

According to the ideal gas equation-

$\mathrm{PV}=\mathrm{nRT}$

here R is the universal gas constant and its value is equal to 0.0821

So, by putting all these values in the equation we get-

$$\begin{gathered} 1.88\times 38=\mathrm{n}\times 0.0821\times 298 \\ \mathrm{V}=\frac{1.88\times 38}{0.0821\times 298} \\ \mathrm{V}=2.92\mathrm{L} \end{gathered}$$