Which of the following is added to chloroform to slow down its aerial oxidation in the presence of light?

Rate constant varies with temperature by the equation $\log _{10} k =5-\frac{2000}{T}$. We can conclude that $\left( R =8.314\ J\ mol ^{-1} K^{-1}\right) :-$

The inverse of the proposition $(p \wedge \sim q) \Rightarrow r$ is

$A$ sonometer wire resonates with a given tuning fork,forming standing waves with five antinodes between the two bridges when a mass of $9 \, kg$ is suspended from the wire. When this mass is replaced by a mass $M$,the wire resonates with the same tuning fork,forming three antinodes for the same positions of the bridges. The value of $M$ is .... $kg$.

At higher altitude,the boiling point of water is $95\,^{\circ}C$. The amount of $NaCl$ added to $1\, kg$ of water $(K_b = 0.52\, K\, kg\, mol^{-1})$ in order to raise the boiling point of the solution to $100\,^{\circ}C$ (assuming $90\%$ ionization of $NaCl$) is ........... $g$.

If $\alpha$ and $\beta$ are the roots of the equation $ax^2+bx+c=0$ and the equation having roots $\frac{1-\alpha}{\alpha}$ and $\frac{1-\beta}{\beta}$ is $px^2+qx+r=0$,then $r=$