In which of the following ionization processes the bond energy increases and the magnetic behaviour changes from paramagnetic to diamagnetic.

When 5 litres of a gas mixture of methane and propane is perfectly combusted at 0^oC and 1 atmosphere, 16 litres of oxygen at the same temperature and pressure is consumed, The amount of heat released from this combustion in kJ ($$\Delta $$H_comb. (CH₄) = 890 kJ mol^$$-$$1, $$\Delta $$H_comb. (C₃H₈) = 2220 kJ mol^$$-$$1) is

Three thermochemical equations are given below
(i)  C_(graphite) + O_2(g) $$ \to $$ CO_2(g); $$\Delta $$_rH^o = x kJ mol^$$-$$1
(ii)  C_(graphite) + $${1 \over 2}$$O_2(g) $$ \to $$ CO_(g); $$\Delta $$_rH^o = y kJ mol^$$-$$1
(iii)  CO_(g) + $${1 \over 2}$$O_2(g) $$ \to $$ CO_2(g); $$\Delta $$_rH^o = z kJ mol^$$-$$1
Based on the above equations, find out which of the relationship given below is correct.

At 100^oC the K_w of water is 55 times its value at 25^oC. What will be the pH of neutral solution? (log 55 = 1.74)