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Percentage of Sucrose Remaining After Hydrolysis Reaction

Sucrose hydrolyses in acidic medium into glucose and fructose by first order rate law with t1/2=3 hourt_{1/2} = 3\text{ hour}. The percentage of sucrose remaining after 6 hours6\text{ hours} is _______. (Nearest integer) (Given : log2=0.3010\log 2 = 0.3010 and log3=0.4771\log 3 = 0.4771)

Official Numerical Answer25

Topics & Concepts

Step-by-Step Solution

To find the percentage of sucrose remaining after 6 hours6\text{ hours}, we use the principles of first-order reaction kinetics.

Step 1: Determine the number of half-lives (nn) The half-life of the reaction is given as t1/2=3 hourst_{1/2} = 3\text{ hours}. The total time elapsed is t=6 hourst = 6\text{ hours}.

The number of half-lives that have passed is: n=tt1/2=6 hours3 hours=2n = \frac{t}{t_{1/2}} = \frac{6\text{ hours}}{3\text{ hours}} = 2

Step 2: Calculate the fraction of sucrose remaining For a first-order reaction, the concentration of the reactant remaining after nn half-lives, relative to its initial concentration [A]0[A]_0, is given by: [A][A]0=(12)n\frac{[A]}{[A]_0} = \left(\frac{1}{2}\right)^n

Substituting n=2n = 2: [A][A]0=(12)2=14\frac{[A]}{[A]_0} = \left(\frac{1}{2}\right)^2 = \frac{1}{4}

Step 3: Calculate the percentage remaining The percentage of sucrose remaining is: Percentage remaining=[A][A]0×100=14×100=25%\text{Percentage remaining} = \frac{[A]}{[A]_0} \times 100 = \frac{1}{4} \times 100 = 25\%

Thus, the percentage of sucrose remaining after 6 hours6\text{ hours} is 25.

Percentage of Sucrose Remaining After Hydrolysis Reaction | Chemistry PYQ Solution - JEE Challenger