A student dissolves 24.3 g Na2S2O3 in enough water to make a 0.302 M solution. How many mL solution did the student make?

Answer 1

We can use the formula:

Molarity = moles of solute / volume of solution in liters

to solve for the volume of the solution.

First, we need to calculate the number of moles of Na2S2O3 in the solution:

moles of Na2S2O3 = mass / molar mass = 24.3 g / (2 x 23.0 g/mol + 3 x 32.1 g/mol) = 0.0787 mol

Next, we can use the formula above to solve for the volume of the solution:

0.302 M = 0.0787 mol / volume (in liters)

Solving for the volume, we get:

volume (in liters) = 0.0787 mol / 0.302 M = 0.260 L

Finally, we can convert the volume to milliliters:

volume (in milliliters) = 0.260 L x 1000 mL/L = 260 mL

Therefore, the student made 260 mL of 0.302 M Na2S2O3 solution.