Assign $A, B, C, D$ from the given type of reaction.
$4KCN + Fe(CN)_2 \downarrow \longrightarrow K_4[Fe(CN)_6]$

${}^{18}_{8}O$ has a half-life of $4650 \ years$. $200 \ mg$ of a sample of ${}^{18}_{8}O$ is reduced to $25 \ mg$ in .......... $years$.

Three taps $A, B, C$ fill up a tank independently in $10 \, h$,$20 \, h$,and $30 \, h$,respectively. Initially,the tank is empty. Exactly one pair of taps is open during each hour,and every pair of taps is open for at least one hour. What is the minimum number of hours required to fill the tank?

Two liquids $A$ and $B$ have $P_A^o$ and $P_B^o$ in the ratio of $1 : 3$ and the ratio of number of moles of $A$ and $B$ in the liquid phase are $1 : 3$. The mole fraction of $A$ in the vapour phase in equilibrium with the solution is equal to:

During meiosis $I,$ the chromosomes start pairing at

The point where the line $\frac{x - 1}{2} = \frac{y - 2}{-3} = \frac{z + 3}{4}$ meets the plane $2x + 4y - z = 1$ is: