Question

7. Which of the following reactions would have a positive value f I. NH3(g) + HCl(g) → NH4Cl(s) 11. Ag+(aq) + Cl-(aq) → AgCl(s) 111, 2H2(g) + O2(g) → 2H2O(g) IV. CakhoBT2 (l) → C6H10 (l) + Br2 (1) V. 2H2O2(g) → 2H2O(g) + O2(g) a). I and II b). I and III c). II and III d). II and IV e). IV and V

Answer 1

QUESTION NUMBER 7:

For given question option (e) is write answer.

• Entropy: entropy is a messure of disorderness.

Solid$\rightarrow$liquid$\rightarrow$gas disorderness increases by this entropy also increases.

For a chemical Change

• If $\Delta$n_g 0 then $\Delta$S 0 Positive i.e entropy of the system increases
• If $\Delta$n_g 0 then $\Delta$S 0 Negative i.e entropy of the system decreases
• $\Delta$n_g$=$ Total number of moles of gaseous products - Total number of moles of gaseous reactents.
• In the given options
• for first three options  $\Delta$n_g 0 then $\Delta$S 0 Negative
• for fourth option $\Delta$n_g  $=$ 0 But no f liquid molecules are increased thats why disorderness increases and $\Delta$S positive
• for fifth option $\Delta$n_g 0 then $\Delta$S 0 Positive i.e entropy of the system increases