(A) For a first-order reaction, the amount remaining after $n$ half-lives is given by the formula $N = N_0 \times (1/2)^n$.Here, the total time is $t

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

(A) For a first-order reaction, the amount remaining after $n$ half-lives is given by the formula $N = N_0 \times (1/2)^n$.Here, the total time is $t = 6 \text{ hours}$ and the half-life is $t_{1/2} = 3 \text{ hours}$.The number of half-lives $n$ is calculated as $n = t / t_{1/2} = 6 / 3 = 2$.The fraction of sucrose remaining is $(1/2)^n = (1/2)^2 = 1/4 = 0.25$.To find the percentage remaining, we multiply the fraction by $100$: $0.25 \times 100 = 25\%$.Thus, $25\%$ of the sucrose remains after $6 \text{ hours}$.

Class 12 Chemistry Chemical Kinetics First Order reaction

Medium

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

JEE MAIN 2026 All JEE MAIN

A
$25$
B
$50$
C
$75$
D
$100$

Explore More

Browse All

Question Bank

All Subjects

Class 12 Questions

Class 12

Chemistry Questions

Chapter

Chemical Kinetics

Subtopic

First Order reaction

Previous Year

JEE MAIN 2026 Paper All JEE MAIN years →

$A \rightarrow$ products is a first-order reaction. The following data is obtained for this reaction at $T \ K$. The value of $x : y$ is:
Rate $(\text{mol } L^{-1} \ \text{min}^{-1})$ $[A]$
$0.2$ $0.02 \ M$
$0.4$ $x \ M$
$1.0$ $y \ M$

Rate $(\text{mol } L^{-1} \ \text{min}^{-1})$	$[A]$
$0.2$	$0.02 \ M$
$0.4$	$x \ M$
$1.0$	$y \ M$

MediumAP EAMCET 2025

View Solution

For a first-order reaction, $20 \text{ mmol}$ of reactant is reduced to $10 \text{ mmol}$ in $1.151 \text{ min}$. Find the rate constant $k$. (in $\text{ min}^{-1}$)

DifficultMHT CET 2026

View Solution

Decomposition of nitrogen pentoxide is known to be a first order reaction. $75\%$ of the oxide had decomposed in the first $24 \ minutes$. At the end of an hour,after the start of the reaction,the amount of oxide left will be

Medium

View Solution

For a first-order reaction,the time taken for the initial concentration to decrease to $1/4$ of its value is $20 \ min$. The time taken for the initial concentration to decrease to $1/16$ of its value will be $......... \ min$.

Medium

View Solution

The reaction $A + B \xrightarrow{k}$ product is first order with respect to $A$ and zero order with respect to $B$. If $a_0$ and $a_t$ are the concentrations of $A$ at $t = 0$ and after time $t \, sec$ respectively,then select the correct relationship -

Medium

View Solution

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial

For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free

For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo

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

Similar Questions

$A \rightarrow$ products is a first-order reaction. The following data is obtained for this reaction at $T \ K$. The value of $x : y$ is:Rate $(\text{mol } L^{-1} \ \text{min}^{-1})$$[A]$$0.2$$0.02 \ M$$0.4$$x \ M$$1.0$$y \ M$

For a first-order reaction, $20 \text{ mmol}$ of reactant is reduced to $10 \text{ mmol}$ in $1.151 \text{ min}$. Find the rate constant $k$. (in $\text{ min}^{-1}$)

Decomposition of nitrogen pentoxide is known to be a first order reaction. $75\%$ of the oxide had decomposed in the first $24 \ minutes$. At the end of an hour,after the start of the reaction,the amount of oxide left will be

For a first-order reaction,the time taken for the initial concentration to decrease to $1/4$ of its value is $20 \ min$. The time taken for the initial concentration to decrease to $1/16$ of its value will be $......... \ min$.

The reaction $A + B \xrightarrow{k}$ product is first order with respect to $A$ and zero order with respect to $B$. If $a_0$ and $a_t$ are the concentrations of $A$ at $t = 0$ and after time $t \, sec$ respectively,then select the correct relationship -

Vedclass Test Series

Exam Paper Generator

Online Exam Module

$A \rightarrow$ products is a first-order reaction. The following data is obtained for this reaction at $T \ K$. The value of $x : y$ is:
Rate $(\text{mol } L^{-1} \ \text{min}^{-1})$ $[A]$
$0.2$ $0.02 \ M$
$0.4$ $x \ M$
$1.0$ $y \ M$