Question

What is the mass of 4.50 mol `Fe`?

Answer 1

Elemental iron has a molar mass of `55.85` `g*mol^-1`

Explanation:

So the mass of the given molar quantity?

`4.50*molxx55.85*g*mol^-1` `~~` `250*g`

Answer 2

4.50 moles `xx` molar mass of Fe
4.50 `xx` 55.9 = ?

Explanation:

Assume that:
n - number of moles
m - mass of substance
M - molar mass (same as atomic weight on periodic table)
`n = m -: M`

4.50 moles (n) has been given to you.

Now find the molar mass (M) of Fe. If you look into your periodic table, the molar mass of Fe is 55.9 g/mol.

To find the mass of substance (m), you need to flip over the formula, therefore, `m = M xx n`
The mass (m) of Fe is:
[55.9 g/mol `xx` 4.50 moles] = 251.6 grams.
Note: It is rounded to the nearest one decimal place.

4.50 moles of Fe should give you 251.6 grams of Fe.