Identify $A$ in the following reaction.
$A + \text{Acetic anhydride} \xrightarrow{H^{+}} \text{Aspirin} + \text{Acetic acid}$

Seven white balls and three black balls are randomly arranged in a row. The probability that no two black balls are placed adjacently is

The transformed equation of $x^2+6xy+8y^2=10$ when the axes are rotated through an angle $\frac{\pi}{4}$ is:

The major product in the following reaction is:

In the arrangement shown in the figure,the masses of blocks $B$ and $A$ are $2m$ and $m$ respectively. The surface between $B$ and the floor is smooth. Block $B$ is connected to block $C$ by means of a string-pulley system. If the whole system is released,find the minimum value of the mass of block $C$ so that block $A$ remains stationary with respect to $B$. The coefficient of friction between $A$ and $B$ is $\mu$.

$Taxa$ differs from $taxon$ due to being