<u>Answer:</u>
(A)
Density = Mass / Volume
So
Mass = Density × Volume


Mole ratio of toluene : Oxygen is 1 : 9

(B)
1 mole of Toluene produces 7 moles of
gas and 4 moles of
Vapour
So the mole ratio is 1 : 11

(C)
1mole contains
molecules

In order to get HgO you would need 2Hg+1O2=2HgO. Since oxygen is diatomic you need two when it stands alone causing you to need two mercuries to balance out the reactants and the product I hope this helps
The answer is Three
!!!!!!