If the concentration of $Al^{3+}$ in an aqueous solution of $Al_2(SO_4)_3$ is $0.28 \ M$,then the concentration of $(SO_4)^{2-}$ ion is ........... $M$.

When $100 \ mL$ of $2 \ M \ KCl$ and $200 \ mL$ of $3 \ M \ K_2SO_4$ solutions are mixed,what will be the molarity of $K^+$ ions in the resulting mixture (in $M$)?

Two solutions of a substance are mixed as follows: $480 \ mL$ of $1.5 \ M$ first solution + $520 \ mL$ of $1.2 \ M$ second solution. The molarity of the final solution will be ............. $M$.

What type of solution is sea water?

If $0.0100 \ g$ of urea $[(NH_2)_2CO]$ is added to $0.3000 \ m^3$ of water,what is the molality of the urea solution?

In a water sample,the concentration of $F^-$ ions is $10 \ ppm$ by weight-volume. What is the concentration of $F^-$ in $\% W/V$ in that solution?