(j)
22 grams / copper molar mass = 0.34375 moles
46 grams / aluminum molar mass = 1.7037037037 moles
2.6 grams / iron molar mass = 0.0465574358 moles

(k)
39 grams of potassium / 39 grams per mole = 1 mole of potassium

1 mole of carbon * 12 grams/mole = 12 grams of carbon

(l)
2 moles, 2 nitrate ions per molecule
4 moles of nitrate ions

(m)
22 grams of carbon / 12 grams per mole = 1.8333 moles of carbon

1.8333 moles of water * 18 grams/mole = 33 grams of water