Chemistry — mixed

For a first order reaction, A $\to$ P, t_1/2 (half-life) is 10 days The time required for ${1 \over 4}$^th conversion of A (in days) is : (ln 2 = 0.693,    ln 3 = 1.1)

If 50% of a reaction occurs in 100 second and 75% of the reaction occurs in 200 secod, the order of this reaction is :

The reaction 2X $\to$ B is a zeroth order reaction. If the initial concentration of X is 0.2 M, the half-life is 6 h. When the initial concentration of X is 0.5 M, the time required to reach its final concentration of 0.2 M will be:

Decomposition of X exhibits a rate constant of 0.05 $\mu$g/year. How many year are required for the decomposition of 5$\mu$g of X into 2.5 $\mu$g?

It is true that :

At $30^{\circ} \mathrm{C}$, the half life for the decomposition of $\mathrm{AB}_{2}$ is $200 \mathrm{~s}$ and is independent of the initial concentration of $\mathrm{AB}_{2}$. The time required for $80 \%$ of the $\mathrm{AB}_{2}$ to decompose is Given: $\log 2=0.30$ $\quad \log 3=0.48$

Integrated rate law equation for a first order gas phase reaction is given by (where $\mathrm{P}_{\mathrm{i}}$ is initial pressure and $\mathrm{P}_{\mathrm{t}}$ is total pressure at time $t$)

$\beta$ - particle is emitted in radioactivity by

The radionucleide ${}_{90}^{234}Th$ undergoes two successive $\beta$ -decays followed by one $\alpha$-decay. The atomic number and the mass number respectively of the resulting radionucleide are

The half-life of a radioactive isotope is three hours. If the initial mass of the isotope were 256 g, the mass of it remaining undecayed after 18 hours would be