Question

Column I		Column II
A	$E_{ a }( f )$	p	$-10 \,kJ \,mol ^{-1}$
B	$E_{ a }( b )$	q	$40 \,kJ\, mol ^{-1}$
C	$\Delta_r H$	r	$30\, kJ\, mol ^{-1}$
D	$E_{\text {Threshold }}$	s	$50 \,kJ \,mol ^{-1}$

• A. A - (b), B - (a), C - (d), D - (c)
• B. A - (c), B - (b), C - (a), D - (d)
• C. A - (a), B - (d), C - (c), D - (b)
• D. A - (d), B - (c), C - (b), D - (a)

Answer 1

Answer: (B)

$( a \rightarrow c )$ Activation energy for forward reaction $=50-20=30\, kJ \,mol ^{-1}$
$( b \rightarrow b )$ Activation energy for backward reaction $=50-10=40\, kJ\, mol ^{-1}$
$( c \rightarrow a ) \Delta_{ t } H=\Delta_{ p } H-\Delta_{ R } H=10-20=$
$-10\, kJ \,mol ^{-1}$
$( d \rightarrow d ) E_{\text {threshold }}=50 \,kJ \,mol ^{-1}$