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#27 Molarity You need to make an aqueous solution of 0.241 M ammonium phosphate

ID: 923530 • Letter: #

Question

#27 Molarity

You need to make an aqueous solution of 0.241 M ammonium phosphate for an experiment in lab, using a 125 mL volumetric flask. How much solid ammonium phosphate should you add?

____grams

How many milliliters of an aqueous solution of 0.235 M potassium acetate is needed to obtain 14.1 grams of the salt?

____ mL

.28 Dilusion

In the laboratory you dilute 2.35 mL of a concentrated 6.00 M nitric acid solution to a total volume of 75.0 mL. What is the concentration of the dilute solution?

_____M

In the laboratory you dilute 4.46 mL of a concentrated 3.00 M nitric acid solution to a total volume of 75.0 mL. What is the concentration of the dilute solution?

_____M

Explanation / Answer

27 )

Molarity = w/Mwt*1000/V in ml

0.241 = (w/53.491)*(1000/125)

W = 1.611 grams

take 1.611 grams of NH4cl and dissolve in minium amount of water and add

water up to 125 ml flask.


No of mol of potassium acetate = 14.1/98.15

   = 0.144 mol

so that ,

Volume of potassium acetate = 0.144/0.235 = 0.613 L

   = 613 ml

M1V1 = M2V2

6*2.35 = M2*75

M2 = 0.188 M


4.46*3 = M2*75

M2 = 0.1784 M