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

Chemistry

Yandel Mccullough

20 July, 10:25

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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Memphis · 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