Question

In the reaction A + 3B → 2C, the rate of formation of C is
(a) the same as rate of consumption of A
(b) the same as the rate of consumption of B
(c) twice the rate of consumption of A
(d) 3/2 times the rate of consumption of B.

Answer 1

Given the reaction is:
.....................A......... + …......3B …...= …..2C..... +...... D
......................a......................a/2................0..............0....................(initially)
......................a-x....................(a/2)-3x..........2x.............x................(at equilibrium)
Here according the equation, 1 mole of A will combine with 3 mole of B and so if x mole of A is consumed then it will combine with 3x mole of B and similarly we can calculate the number of mole of C and D formed(according to their stoichiometric coefficient: just think about this stoichiometry : its very basic and important!!!!)
Now from the question given that, at equilibrium,
(a/2)-3x = 2x
a/2= 5x,
x=a/10
so amount of B reacted=3x=3a/10
Initial amount of B=a/2
so % of B reacted= {3a/10}/{a/2} *100
=6/10 *100=60%

Answer 2

Answer:

in the A+ 3B = C the rate of formation of carbon is