Name the gas that can readily decolourise acidified $KMnO_4$ solution.

The upper half of an inclined plane with an angle of inclination $\phi$ is smooth, while the lower half is rough. $A$ body starting from rest at the top of the inclined plane comes to rest at the bottom of the inclined plane. Then the coefficient of friction for the lower half is

$A$ line with positive direction cosines passes through the point $P(2,-1,2)$ and makes equal angles with the coordinate axes. The line meets the plane $2x+y+z=9$ at point $Q$. The length of the line segment $PQ$ equals

In which of the following reactions,$MgO$ is not formed?

According to the carbinol system,tert-butyl alcohol is named as:

Which complex is likely to show optical activity?