If there were no gravity,which of the following will not be there for a fluid?

Calculate the $pOH$ of a solution at $25\,^{\circ}C$ that contains $1 \times 10^{-10} \, M$ of hydronium ions,i.e.,$H_3O^{+}$.

If $\tan ^{-1} x+\tan ^{-1} y+\tan ^{-1} z=\frac{\pi}{2}$,then $1-xy-yz-zx$ is equal to

$A$ spherical iron ball of $10 \; cm$ radius is coated with a layer of ice of uniform thickness that melts at a rate of $50 \; cm^{3}/min$. When the thickness of ice is $5 \; cm$,the rate (in $cm/min$) at which the thickness of ice decreases is:

The inverse of the matrix $\left[\begin{array}{ccc}7 & -3 & -3 \\ -1 & 1 & 0 \\ -1 & 0 & 1\end{array}\right]$ is

The hydroxides and carbonates of sodium and potassium are easily soluble in water,while the corresponding salts of magnesium and calcium are sparingly soluble in water. Explain.