Question

The number of moles of ethane that occupies $11$ liters at ${27}^{\circ }C$ with a pressure of $3$ atmospheres is $(R=0.082litreatm/(moleK\left)\right)$

• A. $3\times 27/(0.082\times 11)moles$
• B. $0.082\times 11/(3\times 300)moles$
• C. $3\times 11/(0.082\times 300)moles$
• D. $3\times 0.082/(300\times 11)moles$

Answer 1

The correct option is C $3\times 11/(0.082\times 300)moles$

From Ideal gas equation we know, $PV$$=$$nRT$, where $P$ is the pressure exerted by the gas, $V$ is the volume occupied by the gas, $n$ is the number of moles of gas present and $T$ is the temperature.

Here, $P$$=$$3atm$, $V$$=$$11litres$, $T$$=$$(27+273)$, that is $300K$ and $n$ is unknown. Putting all the values in the equation we get,

$PV$$=$$nRT$

$3$$\ast$$11$$=$$n$$\ast$$0.082$$\ast$$300$

Thus, $n$$=$$3$$\ast$$11$$/$$0.082$$\ast$$300$ moles

Hence, option C is the correct answer.