1. Chemistry – Apr 25, 2018
Get out Limiting Reactant Worksheet for HMK check
Do Now – Consider the reaction NH3 + O2  NO + H2O (balance first!!)
If 3.25 g of NH3 are allowed to react with 3.50 g of O2, a) which is the limiting reactant and b) how many grams of NO are formed?
Today’s Objective –
Molarity
Agenda
Hmk Review
Molarity
Solution Stoichiometry
Assignment:
Molarity Worksheet

2. Concentrations of Solutions
The concentration of a solution designates the amount of solute dissolved in a volume of solvent to create a solution.
The greater the amount of solute dissolved in a certain amount of solvent, the more concentrated the solution is.
Qualitatively, concentration can be represented by color intensity.

3. Molarity By far, the most common concentration unit:
Watch your units. Amount of solute must be in moles, not grams. Amount of solution must be in Liters, not mL or grams.
Ex: What is the molarity of a solution of 3.25 mol of NaHCO3 dissolved in 750 mL of water?
Ex: How many moles are there in 75 mL of a 3.5 M NaOH solution?
Ex: What volume of a 1.50 M AlCl3 solution is needed to obtain mol AlCl3?
Ex: What is the molarity of a solution if 75.0 g of Ca(OH)2 is dissolved in 650 mL of water?

4. Complete Stoichiometry
Grams of X
Not Here!!
Grams of Y
Gas Volume of X
Gas Volume of Y
22.4 L
22.4 L
Molar mass
Molar mass
Molarity of X
Molarity of Y
Reaction Coefficients
Moles of X
Moles of Y X X
Macroscopic scale
Volume of X
Volume of Y
6.022x1023
6.022x1023
Reaction Coefficients
Number of X
Number of Y
Atomic scale

5. Solution Stoichiometry Practice
How many grams of NaOH are needed to neutralize 20.0 mL of M H2SO4 solution?
How many liters of M HCl(aq) are needed to react completely with mol of Pb(NO3)2(aq), forming a precipitate of PbCl2(s)?

6. Exit Slip - Homework
Exit Slip: How many moles of HCl are present in 15.3 mL of a M solution?
What’s Due? (Pending assignments to complete.)
Molarity worksheet
What’s Next? (How to prepare for the next day)
Read p , p , 241 p