Question

A chemist prepares a solution of calcium sulfate (CaSO_4) by measuring out 0.0101 g of calcium sulfate 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 calcium sulfate solution. Round your answer to 3 significant digits.

Answer 1

Answer:

2.123x10⁻⁴ M (mol/L)

Explanation:

First, we are considering the molar mass for each element, a data we obtain from the periodic table:

Ca= 40

S= 32

O= 16

Then, for CaSO₄, the molecular mass is 136 g per mol

As we dissolve 0.00101 g of this salt, we are going to convert this mass in moles units:

1 mol CaSO₄=136 g → 0.0101 g=7.43x10⁻⁵ mol

We finally obtain the concentration for the 350 ml, having in mind that it should be in mol/L:

350ml=7.43x10⁻⁵ mol

1000ml (1L)=2.123x10⁻⁴ M , where M=mol/L