On the basis of thermochemical equations (1), (2) and (3), find out which of the algebraic relationships given in options (A) to (D) is correct.
(1) `C_("(graphite)") + O_(2(g)) to CO_(2(g)) , Delta_(r) H= x "kJ mol"^(-1)`
(2) `C_("(graphite)") + (1)/(2) O_(2(g)) to CO_((g)) , Delta_(r ) H= y "kJ mol"^(-1)`
(3) `CO_((g)) + (1)/(2) O_(2(g)) to CO2_((g)) , Delta_(r) H= z "kJ mol"^(-1)`

Options

A. `z= x+y`
B. `x=y-z`
C. `x=y+z`
D. `y=2x-z`

Answer

C

Explanation

The algebraic relationships of the given reaction is equation (A) -equation (B) = equation ( C)
(a) `C_("(graphite)") + O_(2(g)) , Delta_(r) H= x "kJ mol"^(-1)`
(b) `(C_("(graphite)") + (1)/(2) O_(2(g)) to CO_(2(g)) , Delta_(r) H = x "kJ mol"^(-1) )/(CO_((g)) + (1)/(2) O_(2(g)) to CO_(2(g)) , Delta_(r) H = z "kJ mol"^(-1) ) `
Hence, `x-y - z " or " x=y+z`