Chemmystery

Sunday, May 20, 2007

Chemistry topics coming up!

The next few topics will be covered in the first week of June. It would be good to do some reading beforehand.

-Chemical Calculations - Limiting Reagent
-Chemical Calculations - Concentration
-Chemical Calculations - Percentage Purity/Yield
-Acid
-Bases
-Salts

Given the time constrain, it would most likely be stopped at Acids. But it doesn't hurt to read up earlier...does it? :p

Friday, May 4, 2007

Number of molecules (Sec 3)

Mole is a unit.

It is like we all know one dozen is 12.

1 mol is 6 x 10^23.

That is all.

It is that straightforward.

1 mol of carbon dioxide molecules is 6 x 10^23.

But in that, there are 2 moles of oxygen atoms which gives us 2 x 6 x 10^23.

Simple logic. In 1 carbon dioxide molecule, there are 2 oxygen atom. So maturally, the number of oxygen atoms would be twice as much as the number of carbon dioxide molecules.

Think about it.