Answer:
2.07 grams
Explanation:
We know that the molecular mass of [tex]K_2CO_3[/tex] is 138.205 grams.
In order to find out how many grams we need to make 200 mL having a potassium ion concentration of 0.150, we need to find the number of moles first.
M = moles / liters
0.150 = x / 0.200
x = 0.03 moles
Since there are 2 potassium atoms in each molecule of [tex]K_2CO_3[/tex] so we will divide this number by half and multiply it by the molecular mass.
0.03/2 = 0.015 moles
Mass of [tex]K_2CO_3[/tex] needed = 0.015 × 138.205 = 2.07 grams
