Question

If the molar concentration of lead(II) nitrate is 0.926 M, what is the molal concentration of the same solution? The density of the solution is 1.202 g/mL.

Answer 1

Answer:

Following the already established formula as represented below, the molal concentration of the same solution is 1.034m.

Explanation:

Using the formula -

$m = (M * 1000) / (d * 1000) - (M * Molecular mass)$

Where,

m = molality = What we are looking for?

d = density = 1.202 g/mL

M = Molarity = 0.926M

Molecular mass for lead(II) nitrate = 331.2 g/mol

Substituting the values in the question into the equation, we have

m = (0.926 * 1000) / (1.202 * 1000) - (0.926 * 331.2)

    solving for the numerator

   = (0.926 * 1000) = 926

   solving for the denominator

   = (1.202 * 1000) - (0.926 * 331.2)  = 1202 - 306.6912 = 895.3088

    solving for m = molality.........

   = 926/895.3088

m = 1.034m  approximated to three decimal places