Question

Take CuSO4, add enough to create a 0.5 Molar Solution in the ½ liter of water originally in the beaker. (It is fine if the concentration is slightly more or less than 0.5 M, make sure to record the observed concentration).

Required:
a. Show the calculation of the number of moles of in the beaker. (You may need the Equation for Molarity, look it up.)
b. Predict the concentration if the solution is diluted to a volume of 1 liter. Show the calculation of this concentration, include units in all your work.

Answer 1

a. 0.25 moles of CuSO₄

b. 0.25M

Step-by-step explanation:

Molarity is an unit of concentration in chemistry defined as the ratio between moles of solute and volume of solution.

a. As you have 1/2L of water, 0.5L, and you want to have a molarity of 0.5M, the number of moles of CuSO₄ is:

0.5L ₓ (0.5mol / L) = 0.25 moles of CuSO₄

b. If you increase the volume of the solution from 0.5L to 1L, the number of moles of CuSO₄ remain constant, that is, 0.25moles. As the new volume id 1L, the new concentration is:

0.25moles / 1L = 0.25M