`H_(2)(g)+(1)/(2)O_(2)(g)rarr2H_(2)O(l), DeltaH =- 286 kJ`
`2H_(2)(g)+O_(2)(g)rarr2H_(2)O(l)……………kJ(+-?)`

Given that - 2C(s)+2O_(2)(g)rarr 2CO_(2)(g) Delta H = -787 KJ H_(2)(g)+ 1//2O_(2)(g)rarr H_(2)O(l) Delta =-286 KJ C_(2)H_(2)(g)+(5)/(2)O_(2)(g)rarr H_(2)O(l) Delta H=-1310 KJ Heat of formation of acetylene is :-

Calculate the enthalpy of vaporisation for water form the following: H_(2)(g) +1//2O_(2)(g) rarr H_(2)O(g),DeltaH =- 57.0 kcal H_(2)(g) +1//2O_(2)(g) rarr H_(2)O(l),DeltaH =- 68.3 kcal Also calculate the heat required to change 1g H_(2)O(l) to H_(2)O(g)

Given that: i. C(s) + O_(2)(g) rarr CO_(2)(g) , DeltaH =- 94.05 kcal ii. H_(2)(g) +(1)/(2) O_(2)(g) rarr H_(2)O(l), DeltaH =- 68.32 kcal iii. C_(2)H_(2)(g) +(5)/(2) O_(2)(g) rarr 2CO_(2)(g) +H_(2)O(l),DeltaH =- 310.62 kcal The heat of formation fo acetylene is

Find the heat of formation of ethyl alcohol for following data C(s) +O_(2)(g) rarr CO_(2)(g) DeltaH =- 94 kcal H_(2)(g) +1//2O_(2)(g) rarr H_(2)O(l), DeltaH =- 68 kcal C_(2)H_(5)OH(l)+3O_(2)(g) rarr 2CO_(2)(g) +3H_(2)O(l) DeltaH =- 327 kcal

Diborane is a potential rocket fuel which undergoes combustion according to the reaction, B_(2)H_(6) (g) + 3O_(2) (g) rarr B_(2) O_(3) (s) + 3H_(2) O (g) From the following data, calculate the enthalpy change for the combustion of diborane: (i) 2 B (s) + ((3)/(2)) O_(2) (g) rarr B_(2) O_(3) (s) , Delta H = 0 1273 k J//mol (ii) H_(2) (g) + ((1)/(2)) O_(2) (g) rarr H_(2) O (l), Delta H = -286 kJ//mol (iii) H_(2) O (l) rarr H_(2)O (g) Delta H = 44 kJ//mol (iv) 2B (s) + 3H_(2) (G) rarr B_(2) H_(6) (g), Delta H = 36 kJ//mol