Question

$4$g argon (Atomic mass $=40$) in a bulb at a temperature of TK has a pressure P atm. When the bulb was placed in hot bath at a temperature ${50}^o$C more than the first one, $0.8$g of gas had to be removed to get the original pressure. T is equal to :

• A. $510$ K
• B. $200$ K
• C. $100$ K
• D. $73$ K

Answer 1

Answer: (B)

$200$ K

We know that :

$PV=nRT$

Let us consider for argon $P\times V=\frac{4}{40}\times R\times T$

Since,

(molecular weight of $Ar=40$)

On heating,

$P\times V=\frac{3.2}{40}\times R\times \left(T+50\right)$

$4T=3.2T+160$

$T=\frac{160}{0.8}$

$=200K$

Therefore, the correct option is B.