Chemistry 11 Introduction to Molarity Lesson 1

Prescription drugs in the correct concentration make you better. In higher concentration they can kill you.

Chemists need to make solutions that have precise concentrations

Pesticides must be in proper concentrations. Food additives must be in correct concentrations. A driver is legally impaired at 0.08 mg/mL blood alcohol content. Chemists control the concentration of chemicals using the concepts we will develop in this unit.

The concentration of a solution tells you how much solute that is dissolved in a given amount of solvent (water). The molarity is the concentration of a solution. Molarity=# Moles 1 Liter moles of NaCl is dissolved in 4.0 L of water, calculate the molarity. Molarity=

The concentration of a solution tells you how much solute that is dissolved in a given amount of solute (water). The molarity is the concentration of a solution. Molarity=Moles Litre moles of NaCl is dissolved in 4.0 L of water, calculate the molarity. Molarity=2.255 moles 4.0 L

The concentration of a solution tells you how much solute that is dissolved in a given amount of solute (water). The molarity is the concentration of a solution. Molarity=Moles Litre moles of NaCl is dissolved in 4.0 L of water, calculate the molarity. Molarity=2.255 moles 4.0 L =0.56 moles/litre =0.56 M (Molar) where M means moles per 1 litre

g KOH is dissolved in 250. mL of water, calculate the molarity. Molarity=

g KOH is dissolved in 250. mL of water, calculate the molarity. Molarity=5.00 g

g KOH is dissolved in 250. mL of water, calculate the molarity. Molarity=5.00 g x 1 mole g

g KOH is dissolved in 250. mL of water, calculate the molarity. Molarity=5.00 g x 1 mole g L

g KOH is dissolved in 250. mL of water, calculate the molarity. Molarity=5.00 g x 1 mole g L =0.356 M

3.How many moles are there in 205. mL of a M solution?

0.205 L

3.How many moles are there in 205. mL of a M solution? L x0.172 moles 1 L

3.How many moles are there in 205. mL of a M solution? L x0.172 moles= moles 1 L

4.How many grams NaCl are there in mL of M solution?

4.How many grams NaCl are there in mL of M solution? L

4.How many grams NaCl are there in mL of M solution? L x0.500 moles 1 L

4.How many grams NaCl are there in mL of M solution? L x0.500 molesx 58.5 g 1 L 1 mole

4.How many grams NaCl are there in mL of M solution? L x0.500 molesx 58.5 g=7.31 g 1 L 1 mole

5.How many grams of NaCl must be used to prepare a mL of M solution.

L

5.How many grams of NaCl must be used to prepare a mL of M solution L x moles 1 L

5.How many grams of NaCl must be used to prepare a mL of M solution L x moles x 58.5 g 1 L 1 mole

5.How many grams of NaCl must be used to prepare a mL of M solution L x moles x 58.5 g = 1.46 g 1 L 1 mole

6.How many millilitres of a M solution of CoCl 2 will contain 25.0 g?

25.0 g

6.How many millilitres of a M solution of CoCl 2 will contain 25.0 g? 25.0 g x 1 mole g

6.How many millilitres of a M solution of CoCl 2 will contain 25.0 g? 25.0 g x 1 mole x 1 L g mol

6.How many millilitres of a M solution of CoCl 2 will contain 25.0 g? 25.0 g x 1 mole x 1 L x1000 mL g mol 1 L

6.How many millilitres of a M solution of CoCl 2 will contain 25.0 g? 25.0 g x 1 mole x 1 L x1000 mL = 962 mL g mol 1 L

7.Describe how you would prepare mL of a M solution of CoCl L x moles x g = 2.60 g 1 L 1 mole Weigh 2.60 g of CoCl 2 Dissolve in water Transfer to a 100 mL volumetric flask and fill to the line