Question

1. If a solution contains 4.37g of C6H6 and 9.42g of CCl4. What is the molarity of the solution if the solution density is 1.59 g/mL?

A) 7.09

B) 6.45

C) 5.93

D) 0.405

E) 9.44

Please show the steps to solve it as I do not know, thank you for your time.

Answer 1

In the given solution, C₆H₆ is solute and CCl₄ is the solvent.

Mass of solution = Mass of solute (C₆H₆) + mass of solvent (CCl₄)

= 4.37 g + 9.42 g

= 13.79 g

Density of solution = 1.59 g/mL

Calculate the volume of solution as given below

Volume of solution = mass of solution / density of solution

= (13.79 g)/(1.59 g/mL)

= 8.67 mL

= (8.67/1000) L

= 0.00867 L

Volume of solution = 0.00867 L

Molar mass of C₆H₆ = 78.11 g/mol

No. of moles of C₆H₆ = (mass of C₆H₆)/(molar mass of C₆H₆)

= (4.37 g)/(78.11 g/mol)

= 0.0559 mol

Now, calculate the molarity of the solution using following formula

Molarity of solution = (No. of moles of C₆H₆)/(Volume of the solution)

= (0.0559 mol)/(0.00867 L)

= 6.45 M

Molarity of solution = 6.45 M

Thus, Option B) = 6.45 M is correct.