Answer: (a) There are 0.428 moles present in 12 g of
molecule.
(b) There are 2 moles present in
particles of oxygen.
Explanation:
(a). The mass of nitrogen molecule is given as 12 g.
As the molar mass of
is 28 g/mol so its number of moles are calculated as follows.

So, there are 0.428 moles present in 12 g of
molecule.
(b). According to the mole concept, 1 mole of every substance contains
atoms.
Therefore, moles present in
particles are calculated as follows.

So, there are 2 moles present in
particles of oxygen.
Heterogeneous-a mixture of two or more things
solution-a substance that dissolves
suspension-mixture where solid particles do not dissolve
colloid-does not settle and cannot be seperated
Heterogeneous
- tuna casserole
-chocolate chip cookies
-gelatin dessert
-green salad
Solution
-oil (?) depends
Suspension
-vinegar salad dressing
-oil (?) it could go in either catagory
Colloid
-vinegar salad dressing
-oil (?)
Zn(s) + 2HCl(aq) = ZnCl₂(aq) + H₂(g)
zinc + hydrochloric acid = zinc chloride + hydrogen