Question

Can you please tell me the grams i need for these 2 solutions? Thank You

Weigh out the necessary mass of KNO3 to make 50 mL of 1.0 M supporting electrolyte solution. Transfer the KNO3 to a 50- mL volumetric flask and dilute to the mark with deionized Analyte motion water. Ensure the solid is dissolved completely before using the solution. Transfer to a small beaker. This is your supporting electrolyte solution.

Answer 1

The molecular weight of KNO₃ is 101.10 gm/mol and K₃Fe(CN)₆ is 329.24 gm/mol.

1) 101.10 gm in 1000 ml is 1.0 M

101.10 / 1000 gm in 1 ml is 1.0 M

(101.10/1000) x 50 gm in 50 ml is 1.0 M

= 5.055 gm in 50 nm is 1.0 M solution. So you need to weigh 5.055 gm.

2) 0.020 Moles in 1000 ml is 0.020 M solution.

0.020/1000 moles in 1 ml is 0.020 M solution.

(0.020/1000) x 10 moles in 10 ml is 0.020 M solution.

2 x 10^-4 moles in 10 ml

As we know 1 mol = 329.24 gm

then 2 x 10^-4 mol is ( 2 x 10^-4 x 329.24 ) gm = 0.0658 gm