Name: ________________________
Hour: ____ Date: ___________
Chemistry: Dilution of Solutions
Directions: Acids and bases are usually purchased in concentrated form. Rarely, however, do we want to use
the acid or base in its concentrated form – we must dilute it to the exact concentration we want. Use the
table below to help you answer the following questions. As always, show your work to earn full credit.
Concentrated Solution
Molarity of Concentrate (M)
Acetic Acid, Glacial (CH3COOH)
Ammonium Hydroxide (NH4OH)
Formic Acid (HCOOH)
Hydrochloric Acid (HCl)
Hydrofluoric Acid (HF)
Nitric Acid (HNO3)
Perchloric Acid, 60% (HClO4)
Perchloric Acid, 70% (HClO4)
Phosphoric Acid (H3PO4)
Potassium Hydroxide (KOH)
Sodium Hydroxide (NaOH)
Sulfuric Acid (H2SO4)
17.5
14.5
23.6
12.1
28.9
15.9
9.1
11.7
14.8
11.7
19.4
18.0
1. What volume of concentrated hydrochloric acid is needed to make 3.0 L of 1.0 M HCl?
2. What volume of concentrated ammonium hydroxide is needed to make 250 mL of 0.5 M NH4OH?
3. To perform an experiment, you need 0.300 L of 6.0 M nitric acid. You go to the acid cabinet and discover
that you have 100 mL of concentrate. Will you have enough acid to complete the experiment? Show
your calculation and explain your answer.
4. You mix 128 mL of an unknown, concentrated acid with water and get 1.54 L of a 1.5 M acid solution. What
type of acid is it?
5. You need to make 300 L of 2.25 M perchloric acid. It costs $25.95 for a 4.00 liter bottle of 60% HClO4, and
$34.95 for a 4.00 liter bottle of 70% HClO4. Should you buy the 60% or the 70% bottles? Show your
calculations and explain your answer.
6. The process of formation of NaOH in water is extremely exothermic. What special precautions should I
take in mixing this solution? Write down a sequence of steps I should follow to make 1.0 liter of 5.0 M
solution of NaOH? [Be specific…type of glassware to use, etc…]
Name: ________________________
Hour: ____ Date: ___________
Chemistry: Dilution of Solutions
Directions: Acids and bases are usually purchased in concentrated form. Rarely, however, do we want to use
the acid or base in its concentrated form – we must dilute it to the exact concentration we want. Use the
table below to help you answer the following questions. As always, show your work to earn full credit.
Concentrated Solution
Molarity of Concentrate (M)
Acetic Acid, Glacial (CH3COOH)
Ammonium Hydroxide (NH4OH)
Formic Acid (HCOOH)
Hydrochloric Acid (HCl)
Hydrofluoric Acid (HF)
Nitric Acid (HNO3)
Perchloric Acid, 60% (HClO4)
Perchloric Acid, 70% (HClO4)
Phosphoric Acid (H3PO4)
Potassium Hydroxide (KOH)
Sodium Hydroxide (NaOH)
Sulfuric Acid (H2SO4)
17.5
14.5
23.6
12.1
28.9
15.9
9.1
11.7
14.8
11.7
19.4
18.0
1. What volume of concentrated hydrochloric acid is needed to make 3.0 L of 1.0 M HCl?
2. What volume of concentrated ammonium hydroxide is needed to make 250 mL of 0.5 M NH 4OH?
3. To perform an experiment, you need 0.300 L of 6.0 M nitric acid. You go to the acid cabinet and discover
that you have 100 mL of concentrate. Will you have enough acid to complete the experiment? Show
your calculation and explain your answer.
4. You mix 128 mL of an unknown, concentrated acid with water and get 1.54 L of a 1.5 M acid solution. What
type of acid is it?
5. You need to make 300 L of 2.25 M perchloric acid. It costs $25.95 for a 4.00 liter bottle of 60% HClO 4, and
$34.95 for a 4.00 liter bottle of 70% HClO4. Should you buy the 60% or the 70% bottles? Show your
calculations and explain your answer.
6. The process of formation of NaOH in water is extremely exothermic. What special precautions should I take
in mixing this solution? Write down a sequence of steps I should follow to make 1.0 liter of 5.0 M
solution of NaOH? [Be specific…type of glassware to use, etc…]
KEY
Chemistry: Dilution of Solutions
Directions: Acids and bases are usually purchased in concentrated form. Rarely, however, do we want to use
the acid or base in its concentrated form – we must dilute it to the exact concentration we want. Use the
table below to help you answer the following questions. As always, show your work to earn full credit.
Concentrated Solution
Molarity of Concentrate (M)
Acetic Acid, Glacial (CH3COOH)
Ammonium Hydroxide (NH4OH)
Formic Acid (HCOOH)
Hydrochloric Acid (HCl)
Hydrofluoric Acid (HF)
Nitric Acid (HNO3)
Perchloric Acid, 60% (HClO4)
Perchloric Acid, 70% (HClO4)
Phosphoric Acid (H3PO4)
Potassium Hydroxide (KOH)
Sodium Hydroxide (NaOH)
Sulfuric Acid (H2SO4)
17.5
14.5
23.6
12.1
28.9
15.9
9.1
11.7
14.8
11.7
19.4
18.0
1. What volume of concentrated hydrochloric acid is needed to make 3.0 L of 1.0 M HCl?
1.0 M  3.0 L   12.1 M  V2 
M1V1  M 2 V2
V2  0.248 L or 248 mL of 12.1 M HCl
2. What volume of concentrated ammonium hydroxide is needed to make 250 mL of 0.5 M NH 4OH?
0.5 M  0.25 L   14.5 M  V2 
M1V1  M 2 V2
V2  0.0086L or 8.6 mL of 14.5 M NH 4 OH
3. To perform an experiment, you need 0.300 L of 6.0 M nitric acid. You go to the acid cabinet and discover
that you have 100 mL of concentrate. Will you have enough acid to complete the experiment? Show
your calculation and explain your answer.
M 
mol
L
NEED
6M 
x mol HNO 3
0.3 L
x  1.8 mol HNO 3
15.9 M 
M 
mol
L
HAVE
1.8 mol HNO 3
xL
x  0.113 L or 113 mL of 15.9 M HNO 3
15.9 M 
x mol HNO 3
0.04 L
x  0.636 mol HNO 3
113 mL
" need"
- 40 mL
" have"
73 mL
" short"
No, you would need 0.113 L or 113 mL of 15.9 M nitric acid. You would be 73 mL short of HNO 3(aq).
KEY – page 2
Chemistry: Dilution of Solutions
4. You mix 128 mL of an unknown, concentrated acid with water and get 1.54 L of a 1.5 M acid solution. What
type of acid is it?
M1   0.128 L   1.5 M  1.54 L 
M1V1  M 2 V2
M1  18.0 M
 acid must be [H2 SO4]
5. You need to make 300 L of 2.25 M perchloric acid. It costs $25.95 for a 4.00 liter bottle of 60% HClO 4, and
$34.95 for a 4.00 liter bottle of 70% HClO4. Should you buy the 60% or the 70% bottles? Show your
calculations and explain your answer.
$25 .95
 $10.81/lit er
2.4 L
vs.
$34.95
 $12.48/lit er
2.8 L
Step 1) Determine the moles of HClO 4 needed :
M 
mol
L
 " need"
2.25 M 
x mol HClO 4
0.3 L
x  0.675 mol HClO 4
Step 2) Calculate the volume of 60% perchloric acid required :
M 
mol
L
9.1 M 
0.675 mol HClO 4
xL
x  0.074 L of 60% HClO 4
Step 3) Calculate the cost of purchasing 0.074 L of 60% perchloric acid :

$10.81
x $  0.074 L of 60% HClO 4 
1
L
of
60%HClO 4


  $0.80

Step 4) Repeat calculatio ns with 70% perchloric acid and compare :
0.675 mol HClO 4
xL
x  0.0577 L of 70% HClO 4
11.7 M 

$12.48
x $  0.0577 L of 70% HClO 4 
 1L of 70%HClO 4

  $0.72

You should purchase the 70% perchloric acid. The 70% HClO4 acid will save you $0.08/liter used.
KEY – page 3
Chemistry: Dilution of Solutions
6. The process of formation of NaOH in water is extremely exothermic. What special precautions should I take
in mixing this solution? Write down a sequence of steps I should follow to make 1.0 liter of 5.0 M
solution of NaOH? [Be specific…type of glassware to use, etc…]
Step 1) Calculate the mass of sodium hydroxide required.
mol
x mol NaOH
M 
5.0 M 
L
1.0 L
 40.0 g NaOH 
x g NaOH  5.0 mol NaOH 
  200.0 g NaOH
 1 mol NaOH 
Step 2) Add ~800 mL of COLD distilled water to a 1.0 liter volumetric flask.
NEED
x  5.0 mol NaOH
Step 3) Carefully, wearing safety goggles and rubber gloves, add 200 g of NaOH to volumetric flask.
Step 4) Rinse the NaOH powder off the neck of the volumetric flask with distilled water from a squirt
bottle.
Step 5) Mix flask, by swirling gently or place on a shaker to dissolve sodium hydroxide in the water to
create a solution.
Step 6) Allow to cool to room temperature.
Step 7) Slowly, add more distilled water to bring the final volume to 1.0 L.
Step 8) Place a label on the flask with the contents (name and concentration) and date it was made
and your name.
WRONG: 60% does not mean 60% mass:mass
5. You need to make 300 L of 2.25 M perchloric acid. It costs $25.95 for a 4.00 liter bottle of 60% HClO 4, and
$34.95 for a 4.00 liter bottle of 70% HClO4. Should you buy the 60% or the 70% bottles? Show your
calculations and explain your answer.
4.00 L
x 0.6
(60% acid)
2.4 L of HClO 4
$25 .95
 $10.81/lit er
2.4 L
4.00 L
vs.
x 0.7
(70% acid)
2.8 L of HClO 4
$34 .95
 $12.48/lit er
2 .8 L
You should purchase the 60% perchloric acid. The 60% HClO4 acid will save you $1.67/liter used.
M 
mol
L
NEED
2.25 M 
x mol HClO 4
0.3 L
 $1.67 savings
x $  0.675 mol HClO 4 
 1 mol HClO 4
This work is WRONG for #5!
x  0.675 mol HClO 4

  $1.13 savings
