Consider the following reversible reaction,$ A(g)+B(g)\rightleftharpoons AB (g)$. The activation energy of the backward reaction exceeds that of the forward reaction by 2 RT (in J mol-1). If the pre-exponential factor of the forward  reaction is times that of the reverse reaction, the absolute value of $\triangle G^{\ominus}$  ( in J mol-1) for the reaction at 300K is.................                     (Given; ln(2)=0.7 RT =2500J mol-1 at 300K and G is the Gibbs energy )

A) 7500 J/mol

B) 8500 J/mol

C) 6500 J/mol

D) 7000 J/mol


The surface of copper gets tarnished by the formation of copper oxide. N2 gas was passed to prevent the oxide formation during heating of copper at 1250 K. However, the N2 gas contains 1 mole % of water vapor as an impurity. The water vapor oxidizes copper as per the reaction is given below

$2Cu (g)  + H_{2}O (g) \rightarrow Cu_{2}O (s)+H_{2}(g)$

  $P_{H_{2}}$   is the minimum partial  pressure of H2 (in bar) needed to prevent the oxidation at 1250 K. The value of In $P_{H_{2}}$  is........

[Given : total pressure = 1 bar , R  ( universal gas constant ) = 8 JK-1 mol-1 , ln(10)=2.30 Cu(s)  and Cu2 O(s) are  mutually immiscible.)

  At 1250 K

$2 Cu (s)+\frac{1}{2}O_{2}(g)\rightarrow Cu_{2}O (s);$

 $\triangle G^{\ominus} $=-78,000 J mol-1 

$H_{2}(g)+\frac{1}{2}O_{2}\rightarrow H_{2}O (g);$

$\triangle G^{\ominus}$ =-178,000 J mol-1

  G  is the Gibs energy

A) -13.2

B) 13.2

C) 14.6

D) -14.6


In the following reactions sequence, the amount of D (in gram) formed from 10 moles of acetophenone is ...........

 (Atomic weights in g mol -1 : H=1, C=12, N=14, O=16, Br= 80. The yield (%) corresponding to the product in each step  is given in the  parenthesis)



A) 495 g

B) 480 g

C) 525 g

D) 545 g


To measure the quantity of Mncl2 dissolved in an aqueous solution , it was completely converted to KMnO4 using the reaction.

             $MnCl_{2}+K_{2}S_{2}O_{8}+H_{2}O\rightarrow KMnO_{4}+H_{2}SO_{4}+HCl$

  (equation not balanced)

    Few drops of concentrated HCl were added to this solution and gently warmed. Further, oxalic acid (225 mg) was added in portions till the colour of the permanganatic ion disappeared. The quantity of MnCl2 (in mg) present in the initial solution is........

[Atomic weights in g mol -1 : Mn =55, Cl= 35.5]

A) 128mg

B) 115mg

C) 126mg

D) 130mg


 Galena (an ore) is  partially oxidised by passing air through it at high temperature. After some time , the passage of air is stopped, but the heating is continued in a closed furnace such that the content undergo self- reduction. The weight (in kg)of Pb produced per kg of O consumed is............  ( Atomic weights in g mol-1 O= 16, S =32, Pb= 207)


A) 7.25kg

B) 5.26kg

C) 6.85kg

D) 6.47kg