Write down the thermochemical equations for the following reactions:
(i) A 1 mol sample of methane gas reacts with 2 mol of oxygen gas to form 1 mol of carbon dioxide and 2 mol of water. In this reaction, 890.5 kJ of heat is produced.
(ii) A 1 mol sample of carbon (graphite) reacts with 1 mol of oxygen tof orm 1 mol fo carbon dioxide gas. the heat evolved in this reaction is 393.5 kJ.
(iii) 6 mol of carbon dioxide gas reacts with 6 mol of water to form 6 mol of oxygen gas and 1 mol of glucose. the heat absorbed in this reaction is 2200 kJ.

Explanation

(i) `CH_(4)(g)+2O_(2)(g)toCO_(2)(g)+2H_(2)O(l)+890.5kJ`
i.e., `CH_(4)(g)+2O_(2)(g)toCO_(2)(g)+2H_(2)O(l),DeltaH=-890.5kJ`
(ii) C(s, graphite)`+O_(2)(g)toCO_(2)(g)+393.5kJ`
i.e., C(s, graphite)`+O_(2)(g)toCO_(2)(g),DeltaH=-393.5kJ`
(iii) `6CO_(2)(g)+6H_(2)O(l) to C_(6)H_(12)O_(6)(s)+6O_(2)(g)-2800kJ`
i.e., `6CO_(2)(g)+6H_(2)O(l)toC_(6)H_(12)O_(6)(s)+6O_(2)(g),DeltaH=-2800kJ`.