How many grams of cobalt (II) nitrate, Co(NO3)2, are required to make a 2.20%(w/v) aqueous solution in a 250 mL volumetric flask?

Explanation:

Percent means " per hundred," so % m/V means the grams of something in 100 mL of  volume.

Data:

         m/V % = 2.20 %

V of solution = 250 mL

Calculations:

it’s previous models   because when i picked that son of a gun’s answer it was wrong look for previous models because they might make it a different letter