A solution is made by adding 35.5 mL of concentrated hydrochloric acid (37.3 wt%, density 1.19 g/mL1.19 g/mL) to some water in a volumetric flask, and then adding water to the mark to make exactly 250 mL 250 mL of solution. Calculate the concentration of this solution in molarity.

Question

Arabella Singleton

Chemistry

2 July, 04:51

A solution is made by adding 35.5 mL of concentrated hydrochloric acid (37.3 wt%, density 1.19 g/mL1.19 g/mL) to some water in a volumetric flask, and then adding water to the mark to make exactly 250 mL 250 mL of solution. Calculate the concentration of this solution in molarity.

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Answers (1)

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Javier Downs · Answer 1

1.73 M

Explanation:

We must first obtain the concentration of the concentrated acid from the formula;

Co = 10pd/M

Where

Co = concentration of concentrated acid = (the unknown)

p = percentage concentration of concentrated acid = 37.3%

d = density of concentrated acid = 1.19 g/ml

M = Molar mass of the anhydrous acid

Molar mass of anhydrous HCl = 1 + 35.5 = 36.5 gmol-1

Substituting values;

Co = 10 * 37.3 * 1.19/36.5

Co = 443.87/36.6

Co = 12.16 M

We can now use the dilution formula

CoVo = CdVd

Where;

Co = concentration of concentrated acid = 12.16 M

Vo = volume of concentrated acid = 35.5 ml

Cd = concentration of dilute acid = (the unknown)

Vd = volume of dilute acid = 250ml

Substituting values and making Cd the subject of the formula;

Cd = CoVo/Vd

Cd = 12.16 * 35.5/250

Cd = 1.73 M