You wish to prepare 50.00 mL of 0.0350 M NH3 from concentrated ammonia (15.28 M)

Question

You wish to prepare 50.00 mL of 0.0350 M NH3 from concentrated ammonia (15.28 M) by serial dilution using a 50 mL volumetric flasks, a 1.00 mL volumetric pipet, and a 10.00 mL graduated pipet. For the first dilution in the series, 1 mL of concentrated ammonia is added to a 50.00 volumetric flask and then filled to the line. The solution is mixed thoroughly, poured into a beaker, and then used to make the second solution in the series. What volume of the first solution should be used to make the second solution, 50.00 mL of 0.0350 M NH3 solution, using the glassware provided? Select one: a. 5.72 mL b. 2.86 mL c. 5.00 mL d. 0.53 mL e. 2.50 mL

Explanation / Answer

For the first dilution in the series

Vcon = 1ml

Mcon = 15.28 M

Vdil = 50.00ml

Find the concentration of dilute NH3 solution-

The following equation can be used to determine the concentration of dilute NH3 solution.

Molarity concentrated solution × Volume concentrated solution = Molarity dilute solution × Volume dilute solution

The equation is commonly written as: M1V1 = M2V2

15.28 M x 1ml = M2 x 50 ml

M2 = 15.28M x 1ml/50ml

M2 = 0.3056 M

To make the second solution in the series-

Volume of the first solution V1 =?

Molarity of first solution M1= 0.3056 M

Volume of second solution V2 = 50.00 mL

Molarity of second solution M2 = 0.0350 M

We can calculate the volume of first solution V1, by using the equation

M1V1 = M2V2

0.3056 M x V1 = 0.0350 M x 50.00ml

V1 = 50.00 mL x 0.0350M/0.3056M

V1 = 5.726ml

5.72 ml of the first solution should be used to make the second solution.

So, a) 5.72ml is correct.

Related Questions

Navigate

• Browse (All)
• Browse Y
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.