I found some that actually make sense.
These ones are all the electron configurations
This one just shows which group of elements have a tendency to lose or gain electrons
Monday, September 16, 2013
Sunday, September 15, 2013
A very good website for chem!
I found a really helpful website that might help you guys! Since I don't update as fast, this guy is more helpful.
http://www.thattutorguy.com/chemistry-general/
http://www.thattutorguy.com/chemistry-general/
Monday, September 9, 2013
Calculating Molarity.
So let's say there was question like:
A 200 mL solution contains 3.98 g of glucose (C6 H12 O6). What is the molarity of this solution?
The first step is to find the molar mass/ molecular weight.
Carbon: 6 x 12.0107=72.0642
Hydrogen :12* 1.00794=12.09528
Oxygen 6*15.994= 95.664
Now add them all up, you should get:
179.82 grams/mole.
What you have to do know is look at equation again, it says A 200 mL solution contains 3.98 g of glucose, which means the solute is glucose. how much glucose? 3.98 grams of glucose!
so 3.98 is divided by molar mass.
The answer is: 0.022 moles (C6 H12 O6).
You need to know the conversion factor.
1 L/ 1000 mL
You would have to divide 200 mL with 1000 mL.
it would be 0.2 liters.
now just divide 0.022 moles/ 0.2 liters = 0.11 M (molarity)
You would do the same thing molality except it is looking at the solvent and converting grams to kilograms.
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