A chemist prepares a solution of sodium thiosulfate (Na2S203) 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.

Question

Pham

Chemistry

27 August, 08:10

A chemist prepares a solution of sodium thiosulfate (Na2S203) 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.

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Desirae Campos · Answer 1

1.99 M

Explanation:

The molar mass of sodium thiosulfate (solute) is 158.11 g/mol. The moles corresponding to 110 grams are:

110 g * (1 mol/158.11 g) = 0.696 mol

The volume of solution is 350 mL = 0.350 L.

The molarity of sodium thiosulfate is:

M = moles of solute / liters of solution

M = 0.696 mol / 0.350 L

M = 1.99 M