Question

Calculate the molarity of a solution obtained dissolving 10.0 g of cobalt(Ⅱ) bromide hexahydrate in enough water to make 450 mL of solution 7.64 × 10-2 6.80 × 10-2 0.102 M 8.55 × 10-2 6.80 × 10-5

Answer 1

Answer:

The molarity of this solution is 6.8 * 10^-2 M

Explanation:

Step 1: Data given

Mass of CoBr*6H2O = 10.0 grams

Molar mass of cobalt(Ⅱ) bromide hexahydrate =

Volume of the solution = 450 mL = 0.450 L

Step 2: Calculate moles of cobalt(Ⅱ) bromide hexahydrate

Number of moles = Mass / molar mass

Number of moles = 10.0 grams / 326.85 g/mol

Number of moles = 0.0306 moles

Step 3: Calculate molarity of the solution

Molarity = number of moles / volume

Molarity = 0.0306 moles / 0.450L

Molarity = 0.068 M = 6.8 * 10^-2 M

The molarity of this solution is 6.8 * 10^-2 M