Stoichiometry

Question

What mass of oxygen molecules would have the same number of electrons as 147.80 grams of sulfide ions?

Answer 1

How many electrons are in 147.80 g of sulfide ions?

Sulfide ion is S^2-

S normally has 16 electrons as a neutral element.  As a 2- ion, it will have 18 electrons.

147.8 g S2- x 1 mole/32.065 g x 6.02x1023 atoms/mole x 18 electrons/atom = 4.995x10²⁵ electrons

 

Since your question asks about oxygen molecules (not oxygen atoms), it can be assumed to be asking about O₂, not O.

Each O in O₂ has 8 electrons, so in 1 molecule of O₂ there are 16 electrons.

4.995x10²⁵ electrons x 1 molecule O₂/16 electrons = 3.122x10²⁴ molecules O₂

3.122x10²⁴ molecules O₂ x 1 mole O₂/6.02x10²⁴ molecules x 31.998 g/mole =  16.59 grams O₂