Question

a solution contains 10.0g of cobalt (II) chloride in enough ethanol to make exactly 500 ml of a solution. What is its molar concentration

Answer 1

Given:-

→ Mass of Cobalt (II) Chloride = 10.0g

→ Volume of the solution = 500 mL

To find:-

→ Molar concentration [molarity] of the solution.

Solution:-

It is clear, that Cobalt (II) Chloride is solute and ethanol is solvent .

• Molar mass of Cobalt (Co) = 59 g/mol

• Molar mass of Chlorine (Cl) = 35.5 g/mol

Hence, molar mass of Cobalt (II) Chloride [CoCl₂] :-

= 59 + 35.5×2

= 59 + 71

= 130 g/mol

_______________________________

Number of mole in 10g of CoCl₂ :-

= Given Mass/Molar mass

= 10/130

= 1/13

= 0.077 mole

Now, let's convert the volume of the solution from mL to L .

=> 1 mL = 0.001 L

=> 500 mL = 500(0.001)

=> 0.5 L

Molar concentration of a solution :-

= Moles of solute/Liters of solution

= 0.077/0.5

= 0.154 M

Thus, molar concentration of the solution is 0.154M .

Answer 2

Explanation:

Biology

Given:-

→ Mass of Cobalt (II) Chloride = 10.0g

→ Volume of the solution = 500 mL

To find:-

→ Molar concentration [molarity] of the solution.

Solution:-

It is clear, that Cobalt (II) Chloride is solute and ethanol is solvent .

• Molar mass of Cobalt (Co) = 59 g/mol

• Molar mass of Chlorine (Cl) = 35.5 g/mol

Hence, molar mass of Cobalt (II) Chloride [CoCl₂] :-

= 59 + 35.5×2

= 59 + 71

= 130 g/mol

_______________________________

Number of mole in 10g of CoCl₂ :-

= Given Mass/Molar mass

= 10/130

= 1/13

= 0.077 mole

Now, let's convert the volume of the solution from mL to L .

=> 1 mL = 0.001 L

=> 500 mL = 500(0.001)

=> 0.5 L

Molar concentration of a solution :-

= Moles of solute/Liters of solution

= 0.077/0.5

= 0.154 M

Thus, molar concentration of the solution is 0.154M .

hope this helps you!!