NEETChemistryThermodynamics (C)
Given the standard enthalpy change for the reaction: 2 SO ₂( g ) + O ₂( g ) 2 SO ₃( g ) _ r H ^ = -198 ~kJ Match the reactions in List-I with their corresponding enthalpy changes in List-II. List-I List-II (A) SO ₂( g ) + 1 2 O ₂( g ) SO ₃( g ) (I) +198 ~kJ (B) 2 SO ₃( g ) 2 SO ₂( g ) + O ₂( g ) (II) -99 ~kJ (C) SO ₃( g ) SO ₂( g ) + 1 2 O ₂( g ) (III) -396 ~kJ (D) 4 SO ₂( g ) + 2 O ₂( g ) 4 SO ₃( g ) (IV) +99 ~kJ Ch
Options
- AA-(IV), B-(I), C-(II), D-(III)
- BA-(II), B-(I), C-(IV), D-(III)
- CA-(II), B-(IV), C-(I), D-(III)
- DA-(II), B-(I), C-(III), D-(IV)
Correct answer
B. A-(II), B-(I), C-(IV), D-(III)
Step-by-step solution
The base reaction is: 2 SO ₂( g ) + O ₂( g ) 2 SO ₃( g ) _ r H ^ = -198 ~kJ Enthalpy change is an extensive property. When a chemical equation is multiplied by a factor, the enthalpy change is multiplied by the same factor. When a reaction is reversed, the sign of H is reversed. (A) The reaction is divided by 2. H = -198 2 = -99 ~kJ (Matches II) (B) The reaction is reversed. H = -(-198) = +198 ~kJ (Matches I) (C) The reaction is reversed and divided by 2. H = +198 2 = +99 ~kJ (Matches IV) (D) The reaction is multip