Question

What is the concentration of CaCl₂ in the 20 mL solution?

a) 1.5 M
b) 0.75 M
c) 3.0 M
d) 30.0 M

Answer 1

The concentration of CaCl₂ in the 20 mL solution is 0.9 M.

Step-by-step explanation:

To calculate the concentration of CaCl₂ in the solution, we need to first find the number of moles of CaCl₂ and then divide it by the volume of the solution.

Given that 2g of CaCl₂ is dissolved in 150 mL of solution, we can calculate the number of moles using the molar mass of CaCl₂ (110.98 g/mol).

Moles of CaCl₂ = mass of CaCl₂ / molar mass of CaCl₂ = 2g / 110.98 g/mol = 0.018 moles.

Next, we divide the number of moles by the volume of the solution (20 mL), converted to liters: Concentration of CaCl₂ = moles of CaCl₂ / volume of solution in liters = 0.018 moles / 0.02 L = 0.9 M.