If 2 moles of $$\mathrm{C}_6 \mathrm{H}_6(\mathrm{~g})$$ are completely burnt $$4100 \mathrm{~kJ}$$ of heat is liberated. If $$\Delta H^{\circ}$$ for $$\mathrm{CO}_2(\mathrm{~g})$$ and $$\mathrm{H}_2 \mathrm{O}(l)$$ are $$-410$$ and $$-285 \mathrm{~kJ}$$ per mole respectively then the heat of formation of $$\mathrm{C}_2 \mathrm{H}_6(g)$$ is

For an adiabatic change in a system, the condition which is applicable is

$$5.8 \mathrm{~g}$$ of a gas maintained at $$95^{\circ} \mathrm{C}$$ occupies the same volume as $$0.368 \mathrm{~g}$$ of hydrogen gas maintained at a temperature of $$17^{\circ} \mathrm{C}$$ and pressure being the same atmospheric pressure for both the gases. What is the molecular mass of the unknown gas?

Gaseous Nitrous oxide decomposes at $$298 \mathrm{~K}$$ to form Nitrogen gas and Oxygen gas. The $$\Delta \mathbf{H}$$ for the reaction at $$1.0 \mathrm{~atm}$$ pressure and $$298 \mathrm{~K}$$ is $$\mathbf{- 1 6 3 . 1 5} \mathbf{~ k J}$$. Calculate Internal energy change for the decomposition of $$100 \mathrm{~g}$$ of Nitrous oxide gas under the same conditions of temperature and pressure.