Consider the reaction , $2\mathrm{A}+3\mathrm{B}\to 4\mathrm{C}+\mathrm{D}$.Moles of ‘C’ formed when 3 moles of ‘A’ react with 5 moles of ‘B’ will be

              $2\mathrm{A}+3\mathrm{B}\to 4\mathrm{C}+\mathrm{D}$

               2       3        4

Given:    3        5        ?

2moles of A  requires  3moles of B

3 moles of A  requires   ------ =  $\frac{3}{2}\times 3 =4.5\mathrm{moles} \mathrm{of} \mathrm{B}$

$\therefore$ A is the limiting reagent 

Number of moles of C formed = 6moles