Mole quick question

Hi, when using the mole equation (mole = mass/Mr) does the mass have to be in grams or does it not matter as long as all the masses are in consistent units?

grams

Why would it matter if it was in kg or tonnes?

As long as I know that it is

Because the relative masses are in g mol^-1 and so to get the moles from the equation, the mass must be in grams so the g’s cancel.

Let’s try inputting the units of mass and Mr into the formula moles = mass/Mr

(g)/(g mol^-1) = 1/(mol^-1) = mol

Because the relative masses are in g mol^-1 and so to get the moles from the equation, the mass must be in grams so the g’s cancel.

Let’s try inputting the units of mass and Mr into the formula moles = mass/Mr

(g)/(g mol^-1) = 1/(mol^-1) = mol