Question

Given that:
\[\ce{C + O2 -> CO2; ΔH° = - x {k}J}\]
\[\ce{2CO + O2 -> 2CO2; ΔH° = - y {k}J}\]
The heat of formation of carbon monoxide will be ______.

पर्याय

• `(y - 2x)/2`

• y + 2x

• 2x – y

• `(2x - y)/2`

Answer 1

Given that:
\[\ce{C + O2 -> CO2}\]; ΔH° = – x kJ
\[\ce{2CO + O2 -> 2CO2}\]; ΔH° = – y kJ
The heat of formation of carbon monoxide will be `(y - 2x)/2`.

Explanation:

\[\ce{C_{(s)} + O2_{(g)} -> CO2_{(g)}}\]; ΔH° = – x kJ  .....(i)

\[\ce{2CO_{(g)} + O2_{(g)} -> 2CO2_{(g)}}\];  ΔH° = – y kJ  .....(ii)

Adding the two equations above, we obtain,

Equation required:

\[\ce{C_{(s)} + 1/2 O2_{(g)} -> CO_{(g)};}\] is produced by multiplying equation I by two, subtracting the reverse of equation (ii), and dividing the resulting equation by two.

\[\ce{2C_{(s)} + 2O2_{(g)} -> 2CO2{(g)}}\]; ΔH° =  – 2x kJ

\[\ce{2CO2_{(g)} -> 2CO_{(g)} + O2_{(g)}}\]; ΔH° = + y kJ
                                                                                  
\[\ce{2C_{(s)} + O2_{(g)} -> 2CO_{(g)}}\]; ΔH° =  (y – 2x) kJ

Equation required:

\[\ce{C_{(s)} + 1/2O2_{(g)} -> CO_{(g)}}\]; ΔH° = `((y - 2x))/2` kJ