COMEDK · Chemistry · 19. Chemical Kinetics
A radioactive isotope decays at such a rate that after 192 minutes only \(\frac{1}{16}\) of the original amount remains. The half-life of the radioactive isotope is
- A \(12 \mathrm{~min}\)
- B \(24 \mathrm{~min}\)
- C \(32 \mathrm{~min}\)
- D \(48 \mathrm{~min}\)
Answer & Solution
Correct Answer
(D) \(48 \mathrm{~min}\)
Step-by-step Solution
Detailed explanation
For radioactive decay \(t_{1 / 2}=\frac{0.693}{k}\) For concentration to reduce to \(\frac{1}{16}\) of original amount \(\begin{aligned} t &=t_{1 / 2} \times 4 \\ \therefore \quad t_{1 / 2} &=\frac{192}{4}=48 \mathrm{~min} \end{aligned}\)
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Chemistry
- Choose the statements which are incorrect in the case of Lanthanoids.
A. \(\mathrm{Ce}^{4+}\) is diamagnetic while \(\mathrm{Sm}^{3+}\) is paramagnetic.
B. The atomic size of the transition metals having atomic number greater than 71 are very close to that of the elements above them.
C. Lanthanoids react with hot water forming water soluble \(\mathrm{Ln}(\mathrm{OH})_3\) with the liberation of \(\mathrm{O}_2\).
D. The general electronic configuration of Lanthanoids is \((n-2) f^{1-14} 5 d^0 6 s^2\), where \(n=6\).COMEDK 2025 Medium - Number of atoms in \(560 \mathrm{~cm}^{3}\) of oxygen at STP isCOMEDK 2012 Medium
- In a mixture of acetic acid and sodium acetate the ratio of concentrations of the salt to the acid is increased ten times. Then the pH of the solutionCOMEDK 2016 Hard
- Copper has face centred structure with edge length equal to \(361\text{ pm}\). The radius isCOMEDK 2023 Easy
- Thomas slag isCOMEDK 2013 Easy
- The order of acidic strength of boron trihalides isCOMEDK 2023 Medium
More PYQs from COMEDK
- The value of \(\alpha(\neq 0)\) for which the function \(f(x)=1+\alpha x\) is the inverse of itself isCOMEDK 2018 Easy
- If \(A+B+C=180^{\circ}\), then \(\Sigma \tan \frac{A}{2} \tan \frac{B}{2}\) is equal toCOMEDK 2013 Easy
- In Young's double slit experiment, the two slits are separated by \(0.2 \mathrm{~mm}\) and they are \(1 \mathrm{~m}\) from the screen. The wavelength of the light used is \(500 \mathrm{~nm}\). The distance between 6th maxima and 10 th minima on the screen is closest toCOMEDK 2022 Hard
- An AC voltage source of variable angular frequency \(\omega\) and fixed amplitude \(\mathrm{V}_0\) is connected in series with a capacitance \(\mathrm{C}\) and an electric bulb of resistance \(\mathrm{R}\) (inductance zero). When \(\omega\) is decreasedCOMEDK 2024 Medium
- Find the correct matches of the substances, given in Column I, from their characteristic properties given in Column II.
S.No. Column I S.No. Column II W \(
\mathrm{Tl}
\)A Decomposes steam to form its dioxide and dihydrogen gas. X \(
\mathrm{CCl}_4
\)B Consists of twenty 6 -membered rings and twelve 5 membered rings. Y \(\mathrm{Tin}\) C +3 oxidation state is highly oxidising. Z \(
\mathrm{C_{60}}
\)D Electron precise species, neither acts as electron donor nor as electron acceptor. COMEDK 2023 Medium - The mobility of the charge carriers increases withCOMEDK 2024 Easy