Question

calculate the no of moles in 7.85g of fe

Answer 1

Be careful of your capital letters! GM is General Motors. The correct abbreviation is gm for grams. Likewise FE is not a fluorine compound because there is no element E. The correct abbreviation for iron is Fe

Where this could cause problems is CO which is carbon monoxide and Co which is cobalt. But it is important to pay attention to capitals.

To convert grams into number of moles, divide by the molar mass also called standard atomic weight. This is found on the periodic table. For Fe, it’s 55.845 g/mol.

So 7.85 / 55.845 = 0.141 mol. Notice that I didn’t write 0.140567642582147. This is because the mass of iron is measured to 3 significant figures. So the answer is reported to 3 significant figures. It was rounded up.

Hope that helps.

Answer 2

Answer:

The number of moles in 7.85g of iron (Fe) has 0.141 moles.

Explanation:

Atomic weight of Iron (Fe) = 1 mole

We know that atomic weight of Fe = 55.85g

55.85g of iron Fe has no. of moles = 1 mole

7.85g of Fe has no. of moles  $=\frac{1}{55.85}*7.85=0.141moles$

Therefore the given weight of Fe has 0.141 moles.