A reaction requires exactly water molecules

CHEMISTRY · Subjective · A Level · Chemistry · Amount of substance · Amount of substance

Problem

A reaction requires exactly

2.25\,N_A

water molecules, supplied solely from crystals of

\text{CuSO}_4\cdot5\text{H}_2\text{O}

. Calculate the mass of

\text{CuSO}_4\cdot5\text{H}_2\text{O}

that must be weighed out to deliver this quantity of water. Report your answer in grams to three significant figures.