Question

during adiabatic expansion of 2 moles of a gas ,the internal energy of the gas is found to decrease by 2 joules .the work done during the process on gas will be equal to on a new scale of temperature (which is linear)and caled the W scale .the freezing and boiling points of water are 39 degree W and 239 degree W respctvly .wahat will be the temperature on new scale corresponding to a temperature of 39 degree C on celsius scale 1)200 degree w 2)139 degree w 3)78 degree W 4)117 degree W

Answer 1

These are two separate questions:
1-
$$\begin{gathered} ∆\mathrm{Q}=∆\mathrm{U}+∆\mathrm{W} \\ \mathrm{For}\mathrm{adiabatic}\mathrm{change}, \\ 0=-2\mathrm{J}+∆\mathrm{W} \\ \mathrm{Work}\mathrm{done}\mathrm{by}\mathrm{gas}\mathrm{is}\mathrm{given}\mathrm{by}, \\ ∆\mathrm{W}=2\mathrm{J} \\ \mathrm{Thus},\mathrm{work}\mathrm{done}\mathrm{on}\mathrm{the}\mathrm{gas}\mathrm{will}\mathrm{be}-2\mathrm{J}. \\ 2- \\ \frac{{39}^0-0}{{100}^0-0}=\frac{\mathrm{t}-{39}^0}{{239}^0-{39}^0} \\ \mathrm{or}\mathrm{t}={117}^0 \end{gathered}$$