Stoichiometry with Molarity and STP

The past is coming back to haunt us!

MOLARITY AND STP!

this is insane

Let us review what we know about molarity!

• Molarity = moles/litres
• We can also find
• Litres = moles/Molarity
• mole = Molarity x Litres

How about an example? Your negative response has not been heard!

Consider the following equation: Ca(OH)2 + 2 HCL --> CaCl2 + 2H2O

How many litres of 0.100M HCL would be required to react completely with 5.00g of Calcium Hydroxide?

1) Write a balanced equation (it is already balanced)
2) Create a map that gets you from grams of Ca(OH)2 to litres of HCL 
3) 5.00g Ca(OH)2  x  1 mol Ca(OH)2  x   2 mol HCL  =  0.0135 moles HCL

                                     74.1g Ca(OH)2   1 mol Ca(OH)2  

4) Now use the molarity equation to find the amount of litres required

            Litres = 0.0135 moles HCL

                                       0.100M

             Litres = 0.135 L of 0.100M HCL        

Now how about the STP?

Consider the following equation: 2 H2 + O2 --> 2 H2O

Calculate the volume of oxygen gas required to burn 250.0L of Hydrogen gas at STP.

250.0L H2  x  1 mol  x  1 mol O2  x  22.4L   = 125.0L O2

                        22.4L      2 mol H2  1 mol O2

Here is a game to aid you on your quest to conquer the past!

For moles and stoichiometry!