# What is the formality of a 1.24*g mass of "copper sulfate pentahydrate" in a 100*cm^3 volume of solution?

$\text{Formality}$ $=$ $\text{Moles of solute"/"Volume of solution (L)} = 0.05 \cdot m o l \cdot {L}^{-} 1$.
$\text{Concentration of sodium thiosulfate pentahydrate:}$
$\equiv$ $\frac{\frac{1.24 \cdot g}{248.18 \cdot g \cdot m o {l}^{-} 1}}{100 \cdot c {m}^{3} \times {10}^{-} 3 \cdot c {m}^{-} 3 \cdot L}$
$= 0.0500 \cdot m o l \cdot {L}^{-} 1$ WITH RESPECT TO THE PENTAHYDRATE.