Which has a greater mass: 12 mol of salt (NaCl) or 7 mol of silver (Ag)?

7 moles of silver.

Explanation:

Given data:

Moles of NaCl = 12 mol

Moles of Ag = 7 mol

Which have greater mass = ?

Solution:

Mass of NaCl:

Mass = number of moles × molar mass

Mass = 12 mol ×58.5  g/mol

Mass = 702 mol

Mass of Ag:

Mass = number of moles × molar mass

Mass = 7 mol × 107.87 g/mol

Mass = 755.09 mol

Thus 7 mol of silver has greater mas.