SOLUTION CONCENTRATION: MOLARITY

The component which dissolves in a solution is called the

solute

The solvent is usually referred to as the component of a solution which is present as:

the larger quantity, the liquid which dissolves a solid

Which expression defines molarity?

#moles / Liter solution

The molecular weight of NaCl is 58.44 grams/mole. If you had a 1.0 molar solution (1.0 M), you would have to put 58.44 g of salt in 1.0 liter of solution.

How many moles of NaCl would you have in 100 mL of this solution?

0.10

The molecular weight of NaCl is 58.44 grams/mole. If you had a 1.0 molar solution (1.0 M), you would have to put 58.44 g of salt in 1.0 liter of solution.

100 mL of this solution would have ___ grams of NaCl.

5.8

The molecular weight of NaCl is 58.44 grams/mole. If you had a 1.0 molar solution (1.0 M), you would have to put 58.44 g of salt in 1.0 liter of solution.

Suppose that instead of a 1 M solution, you decided to make up a 0.5 M solution.

How many moles of NaCl would there be in one liter?

0.5

The molecular weight of NaCl is 58.44 grams/mole. If you had a 1.0 molar solution (1.0 M), you would have to put 58.44 g of salt in 1.0 liter of solution.

With a 0.5 M solution:

How many moles of NaCl would there be in 1,000 mL?

0.5

Be sure to use proper significant figures.

The molecular weight of NaCl is 58.44 grams/mole. To prepare a 0.50 M solution:

You would need to have ____ grams of NaCl in 1,000 mL of water.

29

The molecular weight of NaCl is 58.44 grams/mole. With a 0.50 M solution:

How many grams of NaCl would there be in 10.0 mL of solution?

0.29

Now dilute 10.0 mL of the 0.50 M NaCl by adding distilled water until 100 mL of solution are produced.

Does the 100 mL of diluted NaCl have more, less, or the same quantity of NaCl as the original 10.0 mL of 0.50 M NaCl?

the same

Consider again the solution made by diluting 10.0 mL of the 0.50 M NaCl by adding distilled water until 100 mL of solution are produced.

Has the concentration of the diluted salt solution increased, decreased, or remained constant?

decreased

Concerning the 10.0 mL of 0.50 M NaCl to 100 mL of solution:

When a solution is diluted, does it change the number of moles dissolved?

no

Concerning the 10.0 mL of 0.50 M NaCl to 100 mL of solution:

Does dilution change the concentration?

yes

When 10.0 mL of the 0.050 M solution are diluted to 100 mL as shown, what is the new concentration?

0.0050 M

If 10.0 mL of the solution on the right are withdrawn from the 100 mL beaker and diluted again in a similar manner, what is the new concentration?

0.00050 M

The molecular weight of NaCl is 58.44 grams/mole. How many grams of NaCl are found in a beaker with 100.0 mL of a 0.0050 M solution? Round answer to 2 significant figures.

0.029

What would be the final volume of the new solution if the 0.2 M solution on the left were diluted to 0.04 M?

50 mL

If water is added to 50 mL of a 0.04 M solution so that it fills a 200 mL beaker, what is the final concentration?

0.01 M

Be sure to use proper significant figures for all remaining problems.

How many grams of NaCl are present in 350 mL of 0.020 M NaCl solution? (Remember that 1 mole NaCl = 58.44 g/mole.)

0.41 g

Calculate the molarity of the solution.

4.32 x 102 moles of CH3COOH in 20.0 liters of water

21.6 M

Calculate the molarity of the solution.

29 g of NaCl in 0.25 liters of water (The molecular weight of NaCl is 58.44 g/mole.)

2.0 M

Calculate the molarity of the solution to 3 digits.

100.0 g of C12H22O11 (molecular weight = 342.28 g/mole) in 1.15 liters of solvent

0.254 M

Calculate the molarity of the solution.

6.02 x 1022 molecules of HCl (molecular weight = 36.5 g/mole) in 2.0 liters of water

0.050 M