The following thermochemical reactions are given: M+(1/2) O 2 arrow M O +351.4 kJ , X+(1/2) O 2 arrow X O +90.8 kJ It follows that the heat of reaction for the following process: M+X O arrow M O +X is given by

Question

The following thermochemical reactions are given: M+(1/2) O 2 arrow M O +351.4 kJ , X+(1/2) O 2 arrow X O +90.8 kJ It follows that the heat of reaction for the following process: M+X O arrow M O +X is given by (A) 442.2 kJ (B) 290.7 kJ (C) -442.2 kJ (D) 260.6 kJ

Tardigrade Admin · Accepted Answer

M+(1/2) O 2 arrow M O +351.4 kJ X+(1/2) O 2 arrow X O +90.8 kJ Subtract (ii) from (i) M-X arrow M O-X O+260.6 kJ ⇒ M+X O arrow M O +X +260.6 kJ

Q. The following thermochemical reactions are given :
$M + \frac{1}{2} O_{2} \to MO + 351.4 k J, X + \frac{1}{2} O_{2} \to XO + 90.8 k J$
It follows that the heat of reaction for the following process : $M + XO \to MO + X$ is given by

$442.2 k J$

$290.7 k J$

$- 442.2 k J$

$260.6 k J$

$M + \frac{1}{2} O_{2} \to MO + 351.4 k J$

$X + \frac{1}{2} O_{2} \to XO + 90.8 k J$

Subtract (ii) from (i)

$M - X \to MO - XO + 260.6 k J$

$\Rightarrow M + XO \to MO + X + 260.6 k J$

Q. The following thermochemical reactions are given : M+21​O2​→MO+351.4kJ,X+21​O2​→XO+90.8kJ It follows that the heat of reaction for the following process : M+XO→MO+X is given by

442.2kJ

290.7kJ

−442.2kJ

260.6kJ