# Chemical Forums

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#### 1961

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« on: February 27, 2019, 05:19:01 AM »

My chemistry teacher gave me this problem. I tried and tried, but I couldn't figure it out and the deadline is tomorrow. Please help me out here friends. This is the problem :

In a compound which is made of element Y, weight percentage of Y is 72% and N( Nitrogen) is 28%. Also, 3 Y atoms are bonded with 2 Nitrogen atoms. Find the followings....
• Chemical formula of the compound.
• Relative molecular mass of Y.

Please guys, if you all know the procedure to solve this kind of problems, please help me out here. I'd really appreciate it. Please be kind enough to include the relevant steps to be taken as well. Thank you very much in advance....
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#### Enthalpy

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« Reply #1 on: February 27, 2019, 05:50:29 AM »

One molecule contains 2 N, you know this mass.
The nitrogen mass makes up 28% of a molecule, so you know the molar mass.
The rest, 72%, is made by 3 atoms of Y : deduce the molar mass of Y, hence the element.

Your teacher cheated with the 72% and 28%, but the molar masses are not integers.
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#### Corribus

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