1 g of a liquid is converted to vapour at 3 × 105 Pa pressure. If 10 % of the heat supplied is used for increasing the volume by 1600 cm 3 during this phase change, then the increase in internal energy in the process will be:

Question

1 g of a liquid is converted to vapour at 3 × 105 Pa pressure. If 10 % of the heat supplied is used for increasing the volume by 1600 cm 3 during this phase change, then the increase in internal energy in the process will be: (A) 4800 J (B) 4320 J (C) 4.32 × 108 J (D) 432000 J

Tardigrade Admin · Accepted Answer

Work done = P Δ V =3 × 105 × 1600 × 10-6 =480 J Only 10 % of heat is used in work done. Hence Δ Q=4800 J The rest goes in internal energy, which is 90 % of heat. Change in internal energy =0.9 × 4800=4320 J

Q. $1 g$ of a liquid is converted to vapour at $3 \times 1 0^{5} P a$ pressure. If $10%$ of the heat supplied is used for increasing the volume by $1600 c m^{3}$ during this phase change, then the increase in internal energy in the process will be:

$4800 J$

$4320 J$

$4.32 \times 1 0^{8} J$

$432000 J$

Work done $= P Δ V$
$= 3 \times 1 0^{5} \times 1600 \times 1 0^{- 6}$
$= 480 J$
Only $10%$ of heat is used in work done.
Hence $Δ Q = 4800 J$
The rest goes in internal energy, which is $90%$ of heat.
Change in internal energy $= 0.9 \times 4800 = 4320 J$

Q. 1g of a liquid is converted to vapour at 3×105Pa pressure. If 10% of the heat supplied is used for increasing the volume by 1600cm3 during this phase change, then the increase in internal energy in the process will be:

4800J

4320J

4.32×108J

432000J