Which of the following are found in extreme saline conditions?

In the case of small cuts,bleeding is stopped by applying potash alum. Here alum acts as

At $90 \, ^\circ C$,the concentration of $[H_3O^+]$ in pure water is $10^{-6} \, M$. What is the value of $K_w$ at this temperature?

The equation $\sqrt{x + 1} - \sqrt{x - 1} = \sqrt{4x - 1}$ for $x \in R$ has:

$A$ closed hollow insulated cylinder is filled with gas at $0^{\circ} C$ and also contains an insulated piston of negligible weight and negligible thickness at the middle point. The gas in one side of the piston is heated to $100^{\circ} C$. If the piston moves $5 ~cm$,the total length of the hollow cylinder is: (in $~cm$)

Two capacitors $C_1$ and $C_2$ in a circuit are joined as shown in the figure. The potential of point $A$ is $V_1$ and that of $B$ is $V_2$. The potential of point $D$ will be