You need to make 500.0 ml of a 2.2 m solution of k so, how many grams of k so,
do you need?

Explanation:

you're already have a molarity in Question

Molarity M = numer of moles (n) / Volume (Liter)

first you must convert ml to L > 500 ml = 0.5 L

so 2.2 = n / 0.5

n = 2.2 × 0.5 = 1.1 moles

now you are already have number of moles and from the question you have K2O and you can calculate Molecular weight for K2O

K=39

O=16

Mw = 2×39 + 16 = 94

now you can calculate how gram do you need from

number of mole = mass (g) / molecular weight for k2o

so => 1.1 = mass / 94

mass = 1.1 × 94 = 103.4 g

good luck