Which of the following is a part of the pistil (gynoecium)?

The $pK_a$ of a weak acid is $4.8$. What should be the ratio of $\frac{[\text{acid}]}{[\text{salt}]}$,if a buffer of $pH=5.8$ is required?

If $A$ and $B$ are events of a random experiment such that $P(A \cup B) = \frac{4}{5}$,$P(\bar{A} \cup \bar{B}) = \frac{7}{10}$ and $P(B) = \frac{2}{5}$,then $P(A)$ equals

In an electrochemicalcell, dichromate ions in aqueous acidic medium are reduced to $Cr ^{3+}$. The current $($in amperes$)$ that flows through the cell for $48.25$ minutes to produce $1$ mole of $Cr ^{3+}$ is $....$ . Use: $1$ Faraday $=96500 C mol ^{-1}$

$A$ ball is dropped from a height $h$ on a floor of coefficient of restitution $e$. The total distance covered by the ball just before the second hit is

Which of the following orders is correct for the heat of hydrogenation of these compounds?