4.0 gm ideal gas is filled in a bulb having volme $ 10 dm^3 at a constant temperature T & constant pressure P. If 0.8 gm gas is removed from the bulb to maintain the original pressure at (T + 125)K temperature, what would be the value of T for a gas having molar mass 40 gm mole ^{-1} $ .
$ So : n_1T_1 = n_2T_2 $ $ {W_1 \over M_1 } \times T_1 = { W_2 \over M_2} T_2 M_1 = M_2 $
$ W_1T_1 = 3.2(T +125) $ 4T= 3.2T + 400 $ \therefore 0.8T = 400 $ $ \therefore T = 500K