List of top Chemistry Questions on Half life asked in MET

For a first order reaction, time required for 99% completion is \(x\) times the time required for 90% completion. Find \(x\).

A certain radioactive isotope \( ^A_Z X \) (half-life = 10 days) decays to give \( ^{A-4}_{Z-2} X \). If 1.0 g of \( X \) is kept in a sealed vessel, find the volume of He accumulated at STP in 20 days. (Molar mass of \( ^A_Z X = 253 \))

Given a sample of radium-226 having half-life of 4 days. Find probability that a nucleus disintegrates after 2 half-lives.

Determine the \(\mathrm{pH}\) of \(0.024\mathrm{\ M}\) hydroxylamine hydrochloride solution. (\(K_b\) of hydroxyl amine is \(10^{-8}\))

Determine solubility of \(\mathrm{AgBr}\) in a \(0.1\mathrm{\ M\ KCN}\) solution. \([K_f \text{ of } [\mathrm{Ag(CN)_2}]^- = 5.6 \times 10^8; K_{sp} \text{ of } \mathrm{AgBr} = 7.7 \times 10^{-13}]\)

Radioactive decay is a:

The rate constant for the first order reaction is 60 s\(^{-1}\). How much time will it take to reduce the concentration of the reactant to \( \frac{1}{16} \)th value?