confuzion...misunderstandings in chemistry and need clarification?

Question

mass of nitrogen reacted = 3.75g
mass of oxide of nitrogen produced = 12.34g

a) what is the mas of oxygen reacted?...
12.34-3.75 rite?
b)what is the ration of the mass of nitrogen reacted to the mass of oxygen reacted?
(i have no idea)
c)using the mass ration in (b), calculate the mass of nitrongen that would react with 16.0 g of oxygen.
d) using a system of relative atomic mass, if we assign an atomic mass to oxygen of 16, what would be the relative atomic mass of nitrogen? assume 1 atom of nitrogen reacts with 1 atom of oxygen.
3) repreat (d) using the evidence that the formula for this oxide of nitrogen is NO2.
f) was the infomration givin in the evidenc suffiecient to determine the atomic mass of nitrogen relative to oxygen?
g) What addtional evidence was needed?

Answer 1

a) correct
b) mass of nitrogen = 3.75, mass of oxygen = 8.59 The ratio is mass of nitrogen/mass of oxygen = 3.75/8.59
c) mass of nitrogen = (mass oxygen given) x (mass nitrogen)/(mass oxygen) This ratio is the one calculated in part b), so the result is 16*(3.75/8.59).
d) The relative mass is the same as the ratio, if they combine 1:1. mass oxygen x (mass nitrogen/mass oxygen) = relative atomic mass nitrogen.
e) Twice as much oxygen is needed. The numerator of the mass ration now represents 2 atoms of oxygen so the atomic mass ratio is (mass nitrogen/2*mass oxygen).
g) You need to know how many atoms of each combine to make the compound.

Answer 2

N(s) + O2 = NO2

a) Yes, 12.34-3.75 = 8.59

b) 3.75:8.59 = 1: 2.3; thus 1 gram of nitrogen reacts with every 2.3 grams of oxygen. If we have 16 grams of oxygen; then the answere to c) 16/2.3 = 6.96 grams of nitrogen


Not sure about the rest.