Thermodynamics ...

The internal energy of a piece of lead when beaten by a hammer will

6.80 g of $$NH_3$$; is passed over heated CuO. The standard heat enthalpies of $$NH_{3}$$, $$CuO(s)$$ and $$H_2O(l)$$ are -46.0, -155.0 and $$-285 0 \: kJ \: mol^{-1}$$ respectively and the change is.
$$NH_3 +(3/2)CuO\longrightarrow \frac{1}{2}N_2(g)+ (3/2)H_2O(l) +(3/2)Cu(s)$$.
If the enthalpy change is 

The enthalpy change for the reaction is:
                   $$XeF_4\longrightarrow Xe^+ +  F^- + F_2 + F; \:  \ \ \ \ \Delta H=?$$

The heat capacities of the following gases at room temperature are such that :

The heat required to raise the temperature of a body by 1 K is called :

For the change, $$C_{diamond}\longrightarrow +C_{graphite}; \:\Delta H=-1.89 \:kJ$$, if 6 g of diamond and 6 g of graphite are separately burnt to yield $$CO_2$$ the heat liberated in first case is:

According to law of conservation of energy, the energy can neither be _______ nor _________ .

For the reaction,
      $$C+ O_2\longrightarrow CO_2; \:      \Delta H=-393\:J$$
 $$2Zn + O_2\longrightarrow 2ZnO;\:    \Delta H=-412J\:J$$

Hess's law is related to:

Which one of the following correctly represents the physical significance of Gibb's energy change?