Preparation of Required Solutions (NOTE: the methanol is used in the NP solution

ID: 810035 • Letter: P

Question

Preparation of Required Solutions

(NOTE: the methanol is used in the NP solution simply to make the solvent conditions analogous to the NPA solution)

measure out 13.9 mg of NP (139.11 g/mol) - record the mass; place into a 100 ml volumetric flask

add 30.0 ml methanol; mix to dissolve

dilute to 100.0 ml total volume with deionized water; mix well

take 5.0 ml of this solution and place in separate container; add 45.0 ml deionized water; mix well

QUESTION: what is the [NP] in the NP stock solution?

mass of NP = 13.9

Mol wt of Np = 139.11

so moles of NP = 0.099 moles

1) added solvent = 100mL

so moalrity = 0.099 X 1000 / 100 = 0.99 M ( stock solution)

2) new molarity

M1V1 = M2V2

0.99 X 5= 50 X M2

M2= 0.099 M