Answer is: the mass of the oxygen is 2.37 grams.
Balanced chemical reaction: 2Mg + O₂ → 2MgO.
m(Mg) = 3.6 g; mass of magnesium.
n(Mg) = m(Mg) ÷ M(Mg).
n(Mg) = 3.6 g ÷ 24.3 g/mol
n(Mg) = 0.149 mol.; amount of the magnesium.
n(O₂) = ?
From chemical reaction: n(Mg) : n(O₂) = 2 : 1.
n(O₂) = n(Mg) ÷ 2.
n(O₂) = 0.149mol ÷ 2.
n(O₂) = 0.075 mol; amount of the oxygen.
m(O₂) = m(O₂) · M(O₂).
m(O₂) = 0.075 mol · 32 g/mol.
m(O₂) = 2.37 g; mass of the oxygen.
Answer: C. Electrochemical cells involve oxidation-reduction reactions.
Explanation: Oxidation occurs at the anode, and reduction occurs at the cathode.
Wear face mask and holy the conical flask or test tube away from your face and body and dont put it on directly on fire or it