Question

A 50 mL sample of a 4.0 mol /L solution of AgNo3 is diluted to a final volume of 250 mL . what is the concentration of the diluted solution?

Answer 1

During the dilution , the number of the moles of silver nitrate AgNO₃ is conserved:

$n_1=n_2$ .

The number of the moles contained in 50 mL ( don’t forget to convert mL to L) of 4.0 M solution is:

$n_1 = c_1V_1 = 4.0\cdot50\cdot10^{-3} = 0.2$ mol.

Making use of the analogical relation for $n_2$ , we calculate the concentration of the diluted solution:

$c_2 = \frac{n_2}{V_2} = \frac{0.2 }{250\cdot10^{-3}} = 0.8$ M.

Answer: The concentration of the diluted solution is 0.8 M.