Question

The mass of CO2 produced from 620 gm mixture of C2H4O2 & O2 , prepared to produce maximum energy is (Combustion reaction is exothermic)


(A) 413.33 gm


(B) 593.04 gm


(C) 440 gm


(D) 320 gm

Answer 1

Final Answer : (C) 440g

Steps and Understanding:
1) Let the mass of Acetic acid (C2H4O2) be x g, then mass of Oxygen gas O2 is (620-x) g.

Molecular Mass of Acetic acid (C2H4O2) = 60g
Molecular Mass of Oxygen Gas (O2) = 32g


2) To produce maximum energy, both reactants should be consumed fully.
To do that,
no. of moles of acetic acid / no. of moles of O2 = 1/2
=> n ( Acetic Acid) * 2 = n( Oxygen) * 1
=>
$\frac{x}{60} \times 2 = \frac{620 - x}{32} \times 1 \\ = > \frac{620 - x}{x} = \frac{16}{15} \\ = > \frac{620 - x}{x} + 1 = \frac{16}{15} + 1 \\ = > \frac{620}{x} = \frac{31}{15} \\ = > x = \frac{620 \times 15}{31} gram$

Mass of acetic acid = x
Let mass of CO2 obtained be (m) gram.

3) Now by observing reaction,
1 / n(Acetic acid) = 2 / n(CO2)
=> n (Acetic acid) * 2 = n(CO2) * 1
=>
$2 \times \frac{x}{60} = \frac{m}{44} \\ = > m = \frac{x \times 44 \times 2}{60} \\ = > m = \frac{620\times15 \times 44 \times 2}{31 \times 60} \\ = > m = 440gram$

Therefore, mass of CO2 obtained is 440grams.