Answer
(a) $\bf {W=83.53\text { N}}$
(b) $\bf {v=12\text { m}^3\text {/kmol}}$ and $\bf {v=0.7046\text { m}^3\text {/kg}}$
Work Step by Step
Given:
No. of moles, $n=0.5 ~\text {kmol}$
Volume of the system, $V=6~\text {m}^3$.
Acceleration due to gravity, $g=9.81~\text {m/s}^2$
To Find:
(a) Weight and (b) specific volume of the system.
Find the mass of the system.
$m=n \times M$
where, n is the no. of moles and M is the molecular weight of ammonia.
Taking the molecular weight of ammonia $M = 17.03 \text { kg/kmol}$ from the Tabe A-1 and find the mass of the system.
$m=n \times M\\
=0.5\times 17.03$
$m=8.515 \text { kg}$
Find the weight of the system.
$W=mg\\
=8.515 \text { (kg)}\times 9.81\text { (m/s}^2)\\
\bf {W=83.53\text { N}}$
Find the specific volume.
$v=\dfrac {V}{n}\\
=\dfrac {6}{0.5}\\
\bf {v=12\text { m}^3\text {/kmol}}$
$V=\dfrac {V}{m}\\
=\dfrac {6}{8.515}\\
\bf {v=0.7046\text { m}^3\text {/kg}}$
