Question

$A+B\to A_3{B}_2$ (unbalanced)
$A_3{B}_2+C\to A_3{B}_2{C}_2$ (unbalanced)
Above two reactions are carried out by taking 3 moles each of A and B and one mole of C. which of the following option is/are correct?

• A. 1 mole of $A_3{B}_2{C}_2$ is formed
• B. $\frac{1}{2}$ mole of $A_3{B}_2{C}_2$ is formed
• C. $\frac{1}{2}$ mole of $A_3{B}_2$ is formed
• D. $\frac{1}{2}$ mole of $A_3{B}_2$ is left finally

Answer 1

Answer: (B), (D)

The correct options are
B $\frac{1}{2}$ mole of $A_3{B}_2{C}_2$ is formed
D $\frac{1}{2}$ mole of $A_3{B}_2$ is left finally

$\begin{array}{ccccc}\text{For first reaction}& 3A& +& 2B\to & A_3{B}_2\\ \text{initial moles}& 3& & 3& 0\\ \text{final moles}& 0& & 3-2=1& 1\\ & & & & \\ \text{For second reaction}& A_3{B}_2& +& 2C\to & A_3{B}_2{C}_2\\ \text{initial moles}& 1& & 1& 0\\ \text{final moles}& 1-\frac{1}{2}=\frac{1}{2}& & 0& \frac{1}{2}\end{array}$

In the first reaction $A$ is the limiting reagent and in the second reaction $C$ is the limiting reagent.