Answer:
Molecular Mass
Explanation:
It's asking for the numerical quantity. That quantity would be the Molecular Mass. Take the sample mass and divide it by the molecular mass to get the number of moles.
(14g N * 2) + (1g H *4) = 32g / mol of N2H4
To get # of moles, divide the sample mass by the molecular mass
25g / 32g = 0.78125 moles