A student needs to make $5.00 \times 10^{1}$ $5.00xx10^1$ mL of a potassium carbonate solution with a concentration of $3.3000 \times 10^{- 2}$ $3.3000xx10^(-2)$ mol/L. What mass of potassium carbonate should they use to make the solution? (Answer to 3 s.d. in g)

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Answer 1 · 2017-05-24T07:30:59

We need a mass of $228 \cdot m g$ $228*mg$ of $potassium carbonate$ $"potassium carbonate"$ ...........

We use the relationship $Concentration = \frac{Moles of solute}{Volume of solution}$ $"Concentration"="Moles of solute"/"Volume of solution"$ .

And thus $"moles of solute"="concentration"xx"volume".......$

So here...............

$"moles"=50*mLxx10^-3L*mL^-1xx3.30xx10^-2*mol*L^-1$

$=1.65xx10^-3*mol$ .

Which represents a mass of ............................

$=1.65xx10^-3*cancel(mol)xx138.21*g*cancel(mol^-1)=0.228*g$ .

A student needs to make 5.00xx10^15.00×1015.00xx10^1 mL of a potassium carbonate solution with a concentration of 3.3000xx10^(-2)3.3000×10−23.3000xx10^(-2) mol/L. What mass of potassium carbonate should they use to make the solution? (Answer to 3 s.d. in g)