Dilution question, "70 wt. % in H2O"?
To make a solution that is 70% solute by weight with $\ce{H2O}$ as the solvent, take 70 $\mathrm{g}$ of solute and add 30 $\mathrm{mL}$ of water. The resulting solution will have a mass of 100 $\mathrm{g}$, 70 $\mathrm{g}$ of which is the solute; hence, 70 wt. % in $\ce{H2O}$.