KCET2015ChemistryThermodynamics (C)
In the reaction ( S + 3 2 O ₂ SO ₃+2 kJ ) and ( SO ₂+ 1 2 O ₂ SO ₃+y ~kJ ) heat of formation of ( SO ₂ ) is
Options
- A( x+y )
- B( x-y )
- C( 2 x-y )
- D( 2 x+y )
Correct answer
C. ( 2 x-y )
Step-by-step solution
Given [ array l S(s)+ 3 2 O₂(g) S O₃(g) ; H₁=2 x k J (1) S O₂(g)+ 1 2 O₂(g) S O₃(g) ; H₂=y k J (2) array ] For reaction [ S(s)+O₂(g) S O₂(g) ; H₃=? k J ] Inverting Eq. (2), we get [ SO ₃(g) SO ₂(g)+ 1 2 O ₂(g) ; H ₄=-y k J (3) ] Adding Eq. (1) and (3), we get [ S(s)+O₂(g) S O₂(g) ; H₃=(2 x-y) k J ]