Half life of a first order reaction is \(36\;hr\). Find out time (in hour) required for concentration of reactant to get reduced by \(90\%\).
Correct Answer: 120
Solution and Explanation
The Correct Answer is :\(120\)
Top Questions on Half life
- The bond angles H-O-N and O-N-O in the planar structure of nitric acid molecule are respectively:
- Observe the following reaction. This reaction represents: \[ 4HCl + O_2 \xrightarrow{CuCl_2, 723K} 2Cl_2 + 2H_2O \]
- A wooden plant accumulates $10 𝑚𝑔 𝑘𝑔^{−1}$ of $^{14}C$ during its life span. A fossil of this plant was discovered and contains $2.5 𝑚𝑔 𝑘𝑔^{−1}$ of $^{14}C$. The age of this fossil at the time of discovery is years (rounded off to the nearest integer).
(Use 5730 years as half-life of $^{14}C$) The half-life of a radioactive nucleus is 5 years. The fraction of the original sample that would decay in 15 years is:
- JEE Main - 2023
- Physics
- Half life
- The number of incorrect statement/s from the following is ____ .
A. The successive half lives of zero order reactions decreases with time.
B. A substance appearing as reactant in the chemical equation may not affect the rate of reaction.
C. Order and molecularity of a chemical reaction can be a fractional number.
D. The rate constant units of zero and second order reaction are mol L–1s–1 and mol–1 Ls–1 respectively.
Questions Asked in JEE Main exam
Let \[ I(x) = \int \frac{dx}{(x-11)^{\frac{11}{13}} (x+15)^{\frac{15}{13}}} \] If \[ I(37) - I(24) = \frac{1}{4} \left( b^{\frac{1}{13}} - c^{\frac{1}{13}} \right) \] where \( b, c \in \mathbb{N} \), then \[ 3(b + c) \] is equal to:
- JEE Main - 2025
- Integration
- Given below are two statements: Statement I: One mole of propyne reacts with excess of sodium to liberate half a mole of H₂ gas. Statement II: Four g of propyne reacts with NaNH₂ to liberate NH₃ gas which occupies 224 mL at STP. In the light of the above statements, choose the most appropriate answer from the options given below:
- JEE Main - 2025
- Organic Chemistry
- Given below are two statements about X-ray spectra of elements:
Statement (I):A plot of \(\sqrt {v}\) (v=frequency of X-rays emitted) vs atomic mass is a straight line.
Statement (II): A plot of v (v=frequency of X-rays emitted)} vs atomic number is a straight line.- JEE Main - 2025
- X-ray Spectra and Moseley's Law
For the thermal decomposition of \( N_2O_5(g) \) at constant volume, the following table can be formed, for the reaction mentioned below: \[ 2 N_2O_5(g) \rightarrow 2 N_2O_4(g) + O_2(g) \] Given: Rate constant for the reaction is \( 4.606 \times 10^{-2} \text{ s}^{-1} \).
- JEE Main - 2025
- Organic Chemistry
- The ratio of the power of a light source \( S_1 \) to that of the light source \( S_2 \) is 2. \( S_1 \) is emitting \( 2 \times 10^{15} \) photons per second at 600 nm. If the wavelength of the source \( S_2 \) is 300 nm, then the number of photons per second emitted by \( S_2 \) is \_\_\_\_\_ \( \times 10^{14} \).
- JEE Main - 2025
- Units and measurement
Concepts Used:
Half-life
The amount of time taken for half of a particular sample to react is known as Half-life.
Half-Life Formula:
We can describe exponential decay by any of the three formulas
