Question

Which of the following reactions will have the value of $\Delta S$ with a negative sign?

• A. $H_{2}O_{(l)} \rightarrow H_{2}O_{(g)}$
• B. $2SO_{2(g)} + O_{2(g)} \rightarrow 2SO_{3(s)}$
• C. $Cl_{2(g)} \rightarrow 2Cl_{(g)}$
• D. $CaCO_{3(s)} \rightarrow CaO_{(s)} + CO_{2(g)}$

Answer 1

Answer: (B)

$2SO_{2(g)} + O_{2(g)} \rightarrow 2SO_{3(s)}$

Answer 2

: $2SO_{2(g)} + O_{2(g)} \rightarrow 2SO_{3(g)}$

$\Delta n_{g} = 2 - 3 = - 1,\Delta S = - ve$