# Molar mass calculation

• Chemistry
Homework Statement:
Assuming that 1 kg of dry air consists of 232 g of oxygen and 768 g of nitrogen (ignore the admixture of other gases), calculate the molar mass of the air.
Relevant Equations:
M = NA(avogadro number) x mo (molecular mass)
pdf file is my solooution l think its wrong

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Chestermiller
Mentor
In the 1 kg of air, how many moles of oxygen are there? How many moles of nitrogen are there? What is the mole fraction of oxygen? Of nitrogen?

In the 1 kg of air, how many moles of oxygen are there? How many moles of nitrogen are there? What is the mole fraction of oxygen? Of nitrogen?
L really have no idea thats why l asking you guys.

Borek
Mentor
232 grams of oxygen is how many moles?

232 grams of oxygen is how many moles?
14.50054377039141 moles (oxygen) 232 g of oxygen
54.830902353873405 moles (nitrogen) 768 g of nitrogen

Last edited:
14.50054377039141 moles (oxygen) 232 g of oxygen
54.830902353873405 moles (nitrogen) 768 g of nitrogen
do l need to just add these together to get the result?

In the 1 kg of air, how many moles of oxygen are there? How many moles of nitrogen are there? What is the mole fraction of oxygen? Of nitrogen?
14.50054377039141 moles (oxygen) 232 g of oxygen
54.830902353873405 moles (nitrogen) 768 g of nitrogen

Chestermiller
Mentor
14.50054377039141 moles (oxygen) 232 g of oxygen
54.830902353873405 moles (nitrogen) 768 g of nitrogen
Wrong. How many atoms are there in molecular oxygen? In molecular nitrogen? What is the molar mass of an oxygen molecule? Of a nitrogen molecule?

Wrong. How many atoms are there in molecular oxygen? In molecular nitrogen? What is the molar mass of an oxygen molecule? Of a nitrogen molecule?
molar mass for oxygen is 16
molar mass for nitrogen is 14

Chestermiller
Mentor
molar mass for oxygen is 16
molar mass for nitrogen is 14
Wrong. Molar mass of O2 is?