When 6.0 g of graphite reacts with dihydrogen to give methane gas, 37.4 kJ of heat is liberated. What is standard enthalpy of formation of $\mathrm{CH}_4(\mathrm{~g})$ ?

Work done when 2 mole of an ideal gas is compressed from a volume of $$5 \mathrm{~m}^3$$ to $$2.5 \mathrm{~m}^3$$ at 300 K, under a pressure of 100 kpa is

If entropy of a solid is greater than zero, at $$T=0$$, it is called

A sample of gas absorbs $$4000 \mathrm{~kJ}$$ of heat and surrounding does $$2000 \mathrm{~J}$$ of work on sample. What is the value of $$\Delta U$$ ?