I would say A but I am not sure
<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

You just need to multiply the total mass by the decimal value of the part that is tin. 133.8*0.103=13.8g (following the rules of significant figures).
The twin primes between 1 and 100 are; (3, 5), (5, 7), (11, 13), (17, 19), (29, 31), (41, 43), (59, 61), (71, 73). Hope this helped<3
The answer is 7. Valence electrons are the electrons in the very last shell, so we need to look at the outer “circle” and count the electrons, or the little black dots. There are 7 in the last shell.