Question

the heat of combustion of solid benzoic acid at constant volume is -321.3 KJ at 300K the heat of combustion at constant pressure s

Answer 1

state some more quantities ...

Answer 2

C6H5COOH(s) + 15/2 O2(g) ----> 7CO2(g) + 3H2O(l)

1 mol          15/2 mol    7 mol

 △ng = np - nR = 7 - (15/2) = - 0.5 mol ;

qv = -312.3 KJ  

qp = qv +  △ng RT ---(1)

qp = -312.3 + (-0.5) x R x

(273 + 27 i.e, 300K)

= -312.3 - 150 R

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