## Answers

**Answer:-**

**Given:-**

wt. of empty graduated cylinder = 3.25 g

wt. of empty graduated cylinder + wt. of sodium thiosulfate = 76.373 g

volume of water added to graduated cylinder (V) = 170.95 mL

As we know that

wt. of sodium thiosulfate (m) = (wt.

Of empty graduated cylinder + wt. of sodium thiosulfate) - (wt. of empty graduated cylinder)

wt. of sodium thiosulfate (m) = 76.373 g - 3.25 g

wt. of sodium thiosulfate (m) = 73.123 g

So the concentration of a solution of sodium thiosulfate is obtained by 73.123 g of solid sodium thiosulfate dissolved in 170.95 mL of water i.e total volume of solution.

therefore

the concentration of a solution of sodium thiosulfate (c) = wt.

Of sodium thiosulfate (m) / volume of water added to graduated cylinder (V)

the concentration of a solution of sodium thiosulfate (c) = 73.123 g / 170.95 mL

**the concentration of a solution of sodium thiosulfate (c) = 0.43 g / mL (i.e the answer)**

or

**the concentration of a solution of sodium thiosulfate (c) = 0.43 g.mL ^{-1} (i.e the answer)**