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?

Answer 1

Answer: The volume of ammonia required from first solution to make second solution is 5.72 mL

Step-by-step explanation:

To calculate the molarity of the diluted solution, we use the equation:

`M_1V_1=M_2V_2` .......(1)

where,

`M_1\text{ and }V_1` are the molarity and volume of the concentrated ammonia solution

`M_2\text{ and }V_2` are the molarity and volume of diluted ammonia solution

We are given:

`M_1=15.28M\\V_1=1mL\\M_2=?M\\V_2=50.00mL`

Putting values in equation 1, we get:

`15.28* 1=M_2* 50.00\\\\M_2=0.3056M`

Now, calculating the volume of ammonia diluted from first dilution to make the required ammonia solution by using equation 1:

We are given:

`M_1` = Molarity of ammonia solution from first dilution = 0.3056 M

`V_1` = Volume of ammonia solution from first dilution = ?

`M_2` = Molarity of ammonia to make second solution = 0.0350 M

`V_2` = Volume of ammonia to make second solution = 50.00 mL

Putting values in equation 1, we get:

`0.3056* V_1=0.0350* 50\\\\V_1=5.72mL`

Hence, the volume of ammonia required from first solution to make second solution is 5.72 mL