A chemistry student must write down in her lab notebook the concentration of a solution of sodium thiosulfate the concentration of a solution equals the mass of what’s dissolved divided by the total volume of solution

Question

The label on the graduated cylinder says empty weight 2.0g
She put some solid sodium thiosulfate into the graduated cylinder and weighed it with the sodium thiosulfate added the cylinder weighted 18.451g
She added water to the graduated cylinder and dissolved the sodium thiosulfate completely then she read the total volume of the solution from the markings on the graduated cylinder the total volume of the solution was 61.6mL
What concentration should the student write down in her lab notebook? Be sure your answer has the correct number of significant digits

Answer 1

To find the concentration, we can use the formula: concentration = mass of solute / volume of solution.

The mass of the sodium thiosulfate added to the graduated cylinder is the difference between the weight of the cylinder with the added sodium thiosulfate and the empty weight of the cylinder:
mass of sodium thiosulfate = 18.451g - 2.0g = 16.451g.

The volume of the solution is given as 61.6 mL.

Substituting the values into the formula:
concentration = 16.451g / 61.6 mL.

Now let's calculate the concentration:
concentration ≈ 0.267 g/mL.

The student should write down a concentration of approximately 0.267 g/mL in her lab notebook.