Question

A chemist prepares a solution of sodium thiosulfate by measuring out of sodium thiosulfate into a volumetric flask and filling the flask to the mark with water. Calculate the concentration in of the chemist's sodium thiosulfate solution. Be sure your answer has the correct number of significant digits.

Answer 1

The question is incomplete, here is the complete question:

A chemist prepares a solution of sodium thiosulfate by measuring out 110. g of sodium thiosulfate into a 350. mL volumetric flask and filling the flask to the mark with water. Calculate the concentration in mol/L of the chemist's sodium thiosulfate solution. Be sure your answer has the correct number of significant digits.

Answer: The concentration of sodium thiosulfate solution is 1.99 mol/L

Explanation:

To calculate the molarity of solution, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{Volume of solution (in mL)}}$

Given mass of sodium thiosulfate = 110 g

Molar mass of sodium thiosulfate = 158.1 g/mol

Volume of solution = 350 mL

Putting values in above equation, we get:

$\text{Molarity of sodium thiosulfate}=\frac{110\times 1000}{158.1\times 350}\\\\\text{Molarity of sodium thiosulfate}=1.99mol/L$

Hence, the concentration of sodium thiosulfate solution is 1.99 mol/L