Question

If $C(s) + O_2(g) \longrightarrow CO_2(g)$; $\Delta H = R$ and $CO(g) + \frac{1}{2} O_2 (g) \longrightarrow CO_2 (g)$; $\Delta H = S$, then heat of formation of CO is:
(a) R + S
(b) R – S
(c) R × S
(d) S – R

Answer 1

B) R - S

If You Will Subtract CO + 1/2O2 → CO2 from C + O2 → CO2

We Will Get C + 1/2O2 → CO

So, R - S is Correct

Answer 2

Hey mate....

here's the answer...

If $C(s) + O_2(g) \longrightarrow CO_2(g)$; $\Delta H = R$ and $CO(g) + \frac{1}{2} O_2 (g) \longrightarrow CO_2 (g)$; $\Delta H = S$, then heat of formation of CO is:

(a) R + S

(b) R – S

(c) R × S

(d) S – R

Option B..

Hope this helps ❤