A spontaneous change is one in which a system under goes

Options

A. No energy change
B. A lowering of free energy
C. A lowering of entropy
D. An increase in internal energy

Answer

B

Explanation

(i) `C_(2)H_(2)(g) + (5)/(2) O_(2)(g) rarr 2CO_(2)(g) + H_(2)O(l) Delta G^(@)= -1234kJ`
(ii) `C(s) + O_(2)(g) rarr CO_(2)(g), Delta G^(@)= -394kJ`
(iii) `H_(2)(g) + (1)/(2) O_(2)(g) rarr H_(2)O(l) , Delta G^(@)= -237kJ`
Eq. (iii) + 2 `xx` Eq. (ii) - Eq.(i) : `H_(2)(g) + 2C(s) rarr C_(2)H_(2)(g), Delta G^(@)= -237 + 2 (-394) - (-1234)kJ`
`Delta G^(@)= +209kJ`