help needed in chemistry_law of multiple proportions?

Question

if a certain oxide of nitrogen weighing 11 g yields 5.6 L of nitrogen at NTP and another oxide of N weighing 15 g yields the same volume of oxygen at NTP , show that it supports law of multiple proportions

NTP = STP = normal/standard temperature and pressure

Answer 1

They key to solving this problem is recognizing that by knowing the volume (Liters) of the Nitrogen gas produced, we can calculate the number of moles of Nitrogen present.

At STP, 1 mole of any ideal gas has a volume of 22.4 Liters.
We will assume Nitrogen gas is an ideal gas.
Therefore, 5.6 Liters of N2 would equate to .25 moles of N2.

In both the 11 gram substance and the 15 gram substance have an equal number of moles of Nitrogen within them, however, each substance has a different mass and therefore must be bonded in a different ("multiple" you might say) proportion with the Oxygen (since the substances were oxides of Nitrogen).

There is really no reason to go any further since it has already been shown that the law of multiple proportions holds true in this case, there is not much need to generate any molecular/empirical formulas for the substances.
However, if you did, you would find that the two subtances have an empirical equation of N2O and NO....which are indeed possible Nitrogen Oxides.

Answer 2

this law stats that "for a given mass of an element the masses of the other element in two or more compounds are in small integers".
now u can get the total pressure exerted by both oxides of nitrogen by the simple gas equation. Pv=nRT where n is the number of moles of gas and R is the gas constant.
thence by taking the ratio of both of these you will come to the conclusion of ihe ratios being in smal integers.
Hence it do supports the law of multiple proportion..

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Answer 3

Google "law of multiple proportions" and get
http://en.wikipedia.org/wiki/Law_of_multiple_proportions