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
