Question

How many moles are their in each of the following?

a) 280g of Silicon

b) 12.04 x 10 25 atoms of phosphorus

c) 19.0 atoms of Fluorine​

Answer 1

a) silicon has at. wt=28 g per mol.

Hence 280 g of silicon is 10 mol of silicon.

b) 1 mol of phosphorous has 6.023 X 10^23 atoms

Hence 12.04 X 10^25 atoms of P has 199 mol in it. (approx.)

c)  1 mol of fluorine has 6.023 X 10^23 atoms.

Hence 19.0 atoms of fluorine has 3.15 X 10^-23 mol in it. (approx.)