Are you ready for your quiz tomorrow?• Take out a scratch sheet of paper, a

pencil/pen, and a calculator

1. A gas at 3 atmospheres has a solubility of 17 g/L. If we changed the pressure to 20 atmospheres, what is the gas’s solubility?

2. We have a 30% solution of sodium chloride. We made this solution by adding 57 grams of salt to how many grams of water?

3. What is the concentration of a solution made from 170 grams of BaCl2 and 300 grams of water?

4. We have 256 grams of a 30% sodium chloride solution. How many grams of salt and how many grams of water were used to make the solution?

5. Don’t forget about your solubility curves!! You’ll see these types of problems tomorrow.

1. A gas at 3 atmospheres has a solubility of 17 g/L. If we changed the pressure to 20 atmospheres, what is the gas’s solubility?

2

2

1

1

P

S

P

S

203

17 x

3x = 340

x = 113 g/L

2. We have a 30% solution of sodium chloride. We made this solution by adding 57 grams of salt to how many grams of water?

%100solution

solute

3010057

x

solventsolutesolution

solutionofgx

190

waterg

water

133

57190

3. What is the concentration of a solution made from 170 grams of BaCl2 and 300 grams of water?

%100solution

solute

100)300170(

170

%100 sovlentsolute

solute

%2.36100470

170

4. We have 256 grams of a 30% sodium chloride solution. How many grams of salt and how many grams of water were used to make the solution?

%100solution

solute

30100256

x

solventsolutesolution

saltsoluteofgx

)(9.76

waterg

water

1.179

9.76256

• Sometimes the terms diluted and concentrated are not specific enough

• Just like in a cooking recipe, in chemistry lab you may need a certain amount to make your experiment work properly

Molarity (M)

• Molarity, M, molar concentration• 2 M = pronounced as 2 molar• Molarity is another way to express concentration as

moles per liter

• This means you need to remember your flow chart so that you can convert from grams to moles if grams is given in the problem!

solutionofLiters

soluteofmolesMolarity

Remember if we’re given grams to get to moles we do

Molar Mass Grams / mole

x

Particles (atoms or

molecules)Moles

Avogadro’s Number

6.02 x 1023 particles/mole

÷

x

Mass (grams)

÷

massmolar

grams

• We can manipulate the molarity equation…

solutionofLiters

solutemolesMolarity

massmolar

gramsmoles

solutionofLiters

massmolargrams

Molarity

What is the molarity of a solution containing 58 grams of sodium chloride in 1 liter of water?

solutionofLiters

massmolargrams

Molarity

1)5.3523(

58Molarity

M1

Calculate the molarity of 100 mL solution containing 50 grams of H2SO4.

• Don’t forget that we must use Liters! • Remember King Henry Died Unexpectantly Drinking Chocolate

Milk– KHDUDCM• 100 mL = 0.1 L

solutionofLiters

massmolargrams

Molarity

1.0)1641.322(

50Molarity M1.5

1.01.98

50

Molarity

How many grams of salt would be dissolved in 1 L of a 0.5 M solution of NaCl

solutionofLiters

soluteofmolesMolarity

15.0

x

NaClofmolesx 5.0

NaClg25.29)5.3523(5.0