I’m stuck on this problem.. please help!

1.72 mol

Explanation:

Given data:

Mass of NaCl = 200 g

Moles of Na₂O formed = ?

Solution:

Chemical equation:

MgO + 2NaCl   →    Na₂O + MgCl₂

Number of moles of NaCl:

Number of moles = mass/ molar mass

Number of moles = 200 g/ 58.44 g/mol

Number of moles = 3.422 mol

Now we will compare the moles of NaCl with Na₂O.

                            NaCl       :          Na₂O

                              2           :               1

                            3.422        :           1/2×3.422 = 1.71 mole

Approximately equal to 1.72 so option A is correct.