Question

For the reaction, 2x + 3y + 4z o 5w Initially if 1 mole of x, 3 mole of y and 4 mole of z is taken and 1.25 mole of w is obtained then % yield of this reaction is _______.
(1) 30%
(2) 50%
(3) 100%
(4) None of these

Answer 1

For the reaction, 2x + 3y + 4z o 5w Initially if 1 mole of x, 3 mole of y and 4 mole of z is taken and 1.25 mole of w is obtained than % yield of this reaction is 50%.

Answer 2

for the reaction, $2x+3y+4z\rightarrow 5w$ initially,

• number of moles of x = 1
• number of moles of y = 3
• number of moles of z = 4

from reaction, it is clear that 2 moles of x reacts with 3moles of y and 4 moles of z. but given, 1 mole of x for 3 moles of y and 4 moles of z. hence, x is limiting reagent.

it means, product is formed along with x.

in reaction, 2 moles of x produced 5 moles of w.

so, 1 moles of x produced 2.5 moles of w.

but only 1.25 moles of w is obtained.

so, % yield = experimental value/theoretical value × 100

= 1.25/2.5 × 100

= 50 %

hence, option (2) is correct choice .