Molarity and Stoichiometry

This is an add-on from the previous blog.
This add-on costs $19.99
If you purchase this add-on you will be one step closer in reaching your Stoichiometriness.

BUY NOW

Aight, since you bought this add-on you will learn about Molarity.

Lets start with some examples

Eg. How many grams of Calcium will be formed when 100mL of 0.500M CuSO4 is reacted with sufficient Ca?

FIRST Make the equation
1 CuSO4 + 1 Ca ----> 1 CaSO4 + 1 Cu
Second Check if it is balanced
Now convert mL to L and convert to moles
0.100 L x 0.500Mol CuSO4
                ---------------- = 0.05 moles CuSO4
                         1 L
Now convert moles of CuSO4 to moles of Ca

0.05 mol CuSO4 x 1 mol Ca
                              ----------             =   0.05 moles
                              1 mol CuSO4
Now convert moles of Ca to grams by multiplying by the molar mass of Ca

0.05 mol Ca x 40.1g Ca
                       ---------    =   2.005 grams (REMEMBER SIG FIGS) =  2 grams
                       1 mol Ca

Here is a video to help you



Another part of your add-onn is
GAS STOICHIOMETRY (STP)

Here is an example of a gas stoichiometry problem

Zinc Carbonate decomposes into CO2 and Zinc Oxide. How many grams of ZnCo3 are needed to produce 8.0L of CO2 measured at STP?

First make your equation and balance it
1 ZnCO3 ---> 1 CO2 + 1 ZnO

Then convert litres into moles of CO2 to moles of ZnCO3

8.0L x 1 mol C02           1 mol ZnCo3    
           -----------      x   -------------- =   0.35714 moles ZnCO3
           22.4L CO2          1 mol Co2
NOW convert moles of ZnCo3 to grams

0.35714 mol ZnCo3 x  125.4 g ZnCO3
                                    ----------------  =  44.785356g ZnCO3 Round to sig figs 45g ZnCO3
                                      1 mol ZnCO

If you are still having some problems, please visit this website for more info
http://www.chemtutor.com/xmol2.htm