Which of the following can be used to extinguish a fire caused by alkali metals?

Which of the following reactions defines $\Delta H_f^o$?

Which of the following is not a synthetic polymer?

An elevator weighing $6000\, kg$ is pulled upward by a cable with an acceleration of $5\, m/s^2$. Taking $g$ to be $10\, m/s^2$,then the tension in the cable is ........... $N$.

$A$ molecule $(X)$ has $(i)$ four sigma bonds formed by the overlap of $sp^2$ and $s$ orbitals,$(ii)$ one sigma bond formed by $sp^2$ and $sp^2$ orbitals,and $(iii)$ one $\pi$ bond formed by $p_z$ and $p_z$ orbitals. Which of the following is $X$?

The magnetic moment produced in a substance of $1\,g$ is $6 \times 10^{-7}\,A\cdot m^2$. If its density is $5\,g/cm^3$,then the intensity of magnetization in $A/m$ will be: