1)

If C(s)+O2(g)CO2(g);  H=X     

CO(g)+12O2(g)CO2(g);   H=Y  .

Calculate  fH for CO (g) formation


A) -Y-X

B) Y-X

C) X+Y

D) X-Y

Answer:

Option B

Explanation:

C(s)+O2(g)CO2(g);H1=x     ...........(i)

CO(g)+12O2(g)CO2(g);H2=y  ...........(ii)

 For the formation of CO subtract Eqs.(ii) from (i)  i.e,

  C(s)+O2(g)CO2(g)

CO(g)()+12O2(g)()CO2(g)()_

C(s)+12O2(g)CO(g)_

     rH for formation of CO=  H1H2

                                                                    =-x+y   or y-x