The oxidation number of $C$ in $HNC$ is .......

$CH_3COOH \xrightarrow{LiAlH_4} A$
$A + CH_3COOH \xrightarrow{H_3O^{+}} B + H_2O$
In the above reactions '$A$' and '$B$' respectively are

Choose the correct statement$(s)$:
$(A)$ The position of the centre of mass of a system is dependent on the choice of the coordinate system.
$(B)$ Newton's second law of motion is applicable to the centre of mass of the system.
$(C)$ Internal forces cannot change the state of the centre of mass.
$(D)$ Internal forces can change the state of the centre of mass.

If $3x^2-11xy+10y^2-7x+13y+k=0$ denotes a pair of straight lines,then the point of intersection of the lines is

In algae with a haplontic life cycle,which of the following processes involves mitosis?

How many $H$ atoms are present in $0.046 \, g$ of ethanol $(C_2H_5OH)$?