Question

What mass (g) of barium chloride is contained in 50.0 mL of a barium chloride solution that has a chloride ion concentration of 0.390 M

Answer 1

4.06 g BaCl₂

Step-by-step explanation:

Molarity (M) is given by this formula:

• 
  `\displaystyle \bf{M = (moles \ of \ solute)/(Liters\ of\ Solution) = (mol)/(L)`

We are given M and L in this equation; we can solve for moles of BaCl₂ and use stoichiometry to convert this amount to grams.

First convert 50.0 mL to L:

• 50.0 mL → 0.05 L

Plug this value for L and 0.390 for M into the equation.

• 
  `\displaystyle \bf{0.390=(mol)/(.05)`

Solve for mol by multiplying .05 to both sides.

• 
  `\bf{mol = .0195`

We have .0195 mol BaCl₂. Now let's use stoichiometry to calculate the amount of grams in .0195 mol BaCl₂.

The molar mass of BaCl₂ is 208.23 g so by using stoichiometry...

• 
  `\displaystyle \bf{.0195 \ mol \ BaCl_2 \cdot (208.23 \ g\ BaCl_2)/(1\ mol\ BaCl_2) = 4.060485\ g \ BaCl_2`

There are 4.06 g of BaCl₂ in this solution.