1. CALCULATING CONCENTRATION OF SOLUTIONS
1. Mass Percent = (mass of solute/mass of solution)100
2. Parts per million = (mass of solute/mass of solution)106
3. Mass/volume percent = (mass of solute/mL solution)100
4. Volume percent = (mL solute / mL solution)100
5. Molarity = moles solute / L solution

2. CALCULATING CONCENTRATION OF SOLUTIONS
How many grams of a solution that is 32.7% by mass NaCl would contain 45.0 g of NaCl?
Mass % = (mass of solute /mass of solution) 100
32.7 % = (45.0 g / x )100
x = 45.0 g / 0.327
x = mass of solution = 138 g

3. CALCULATING CONCENTRATION OF SOLUTIONS
How much solute is present in mL of a 14.7% (mass/volume) HCl solution?
Mass/volume % = (masssolute/volumesolution) 100
14.7 % = (x / mL )100
x = (756.1 mL)
x = mass of solute = 111g

4. CALCULATING CONCENTRATION OF SOLUTIONS
A 350 mL sample of drinking water was analyzed and found to contain g of sulfate salts. Calculate the concentration of sulfate salts in this water sample?
Masswater = densitywater (Volumewater)
= 1.00 g/mL (350 mL)
= 350 g solution
ppm = (masssolute/masssolution) 106
ppm = (0.0046g / 350 g ) 106
ppm = 13 ppm
Use ppm for trace amounts of solute.

5. PRACTICE PROBLEMS calculating the CONCENTRATION OF SOLUTIONS
___1. How many grams of a 45.0 % Mg(OH)2 solution can be made from 7.00 g of solid Mg(OH)2?
___2. How many kilograms of a 6.8% KC2H3O2 solution will contain 5.3 moles of KC2H3O2?
___3. If g of a 25.0 % sucrose solution was prepared, how many grams of a 5.00% solution of sucrose would contain the same amount of sugar?
15.6 g
7.6 kg
673 g