Which of the following bonds is the most polar?

Sodium metal reacts with $Al_2O_3$ at high temperature to give a sodium compound $X$. Compound $X$ reacts with $CO_2$ in water to give $Y$. What is $Y$?

What do mast cells secrete?

$A$ uniform rod of mass $M$ and length $L$ is placed on a smooth horizontal surface. $A$ horizontal force $F$ is applied at one end of the rod perpendicular to its length. The acceleration of the centre of mass of the rod is:

If $y=y(x)$ is the solution of the differential equation $\frac{5+e^x}{2+y} \cdot \frac{dy}{dx} + e^x = 0$ satisfying $y(0)=1$,then a value of $y(\log_e 13)$ is

Let $f: R \rightarrow R$ be a function such that $f(x)=x^3+x^2 f^{\prime}(1)+x f^{\prime \prime}(2)+6, x \in R$,then $f(2)$ is