Sulphur trioxide is dissolved in heavy water to form a compound $X$. The hybridisation state of sulphur in $X$ is :

$A$ piece of metal weighs $45 \ g$ in air and $25 \ g$ in a liquid of density $1.5 \times 10^3 \ kg \ m^{-3}$ kept at $30^{\circ} C$. When the temperature of the liquid is raised to $40^{\circ} C$,the metal piece weighs $27 \ g$. The density of liquid at $40^{\circ} C$ is $1.25 \times 10^3 \ kg \ m^{-3}$. The coefficient of linear expansion of the metal is

If the curves $x^2+p y^2=1$ and $q x^2+y^2=1$ are orthogonal to each other,then

Most suitable method of introducing alien $DNA$ into a plant cell is

Which one of the following exhibits enantiomerism?

The vectors $3\,i + j - 5\,k$ and $a\,i + b\,j - 15\,k$ are collinear,if