Question

.What is the significance of symbol ‘aq.’?

.How many atoms of oxygen are present in 0.1 mole of water?

Answer 1

(1) The symbol 'aq' stands for aqueous. Aqueous basically means that in the given solution or medium water is present as the solvent.

(2) The chemical formula for water is H₂O. We know that one mole of a substance contains 6.022 X 10²³ particles. Thus

number of molecules of water in one mole of water = 6.022 X 10²³

number of molecules of water in 0.1 moles of water = 0.1 X 6.022 X 10²³ = 6.022 X 10²²

Now, there is one oxygen atom in one molecule of water. Thus,

number of oxygen atoms in one molecule of water = 1

number of oxygen atoms on 6.022 X 10²² molecules of water = 1 X 6.022 X 10²²

Thus, there are 6.022 X 10²² atoms if oxygen in 0.1 moles of water.