Driving off oxygen from a compound

[rasen58]

A 98 gram sample of silver oxide is heated in an open container until all the oxygen has been driven off. What is the total mass of silver remaining in the container?

 

I used to know how to do such problems, but I'm not sure where to start. I know the mass of silver is 107.9 and oxygen's is about 16, so the molar mass of AgO would be 123.9 g/mol, but I'm not sure what to do after that.

Edited January 8, 2014 by rasen58

[hypervalent_iodine]

You can do it a couple of ways, but the simplest is probably by looking at the mass percentage of silver in AgO. Are you familiar with how to do this?

[rasen58]

No, not really.

[hypervalent_iodine]

Alright, well you should know that the mass of a compound is the sum of the mass of its components. NaCl, for example has a molar mass of 58.45 g / mol, of which 35.45 g / mol is Cl and 23 g / mol comes from the Na. We can also express these values as a percentage of the total mass (this is the mass %) and use those numbers to work out the mass of each component of a compound in a given sample. For example:

 

 

 

 

Does that make sense? See if you can try that approach with your question, or otherwise I can show you how to do it using number of moles and stoicheometric ratios.

[rasen58]

Ohh, I see! Thank you!