Acid is a chemical substance that ionises in water to produce hydrogen ions (H+). Acids only show their acidic properties when water is present. In water, hydrochloric acid turns litmus paper red and allows electricity to conduct, but in dry methylbenzene it does not change litmus color or allow conductivity. Similarly, alkalis like ammonia only demonstrate their alkaline properties in water, not in dry solvents.

1. Acid is a chemical substance that Acids Bases
ionises in water to produce
hydrogen ion, H + .
Organic Mineral
Ethanoic HNO3
Methanoic HCl
H2SO
4
H
Cl H
Hydrogen Cl
chloride Cl
H

2. Acid is a chemical substance that Acids Bases Substance that reacts
ionises in waterthehydrogenof ionisable
Basicity – to produce
number with acid to form a salt
of atom per
hydrogen ion, H + .
molecule of an acid and water only
Organic Mineral
Na2O + 2HCl g 2NaCl+ H2O
Ionisation of acidEthanoic Basicity
HNO3
Methanoic HCl NaOH + HCl g NaCl + H2O
HClg H++ Cl- monoprotic
H2SO Bases
4
H2SO4g2H++ SO42- diprotic All metal oxide and
metal hydroxide.
alkali
H3PO4g 3H++ PO42- triprotic Bases that dissolve
in water and produce
Hydroxide ion, OH-
CH3COOH gCH3COO- + H+
H H + +
Soluble base Insoluble base
Cl-
(alkali) (base)
Hydrochloric Cl- Cl-
acid H+ Sodium oxide Copper(II) oxide
Hydroxonium ions Potassium oxide Copper(II) hydroxide
H2O Sodium hydroxide
HCl g H3O+ + Cl- Zinc hydroxide
Potassium hydroxide Aluminium Oxide
HClgH++ Cl Barium hydroxide
-
H3O+ g H+ + H2O Lead(II) hydroxide
Ammonia Magnesium hydroxide

3. Acids Bases
pH Scale
acid neutral alkali
pH1 pH2 pH3 pH6 pH7 pH8 pH12 pH13 pH14
Strong acid Weak acid Weak alkali Strong alkali
an acid that an alkali that
an acid that partially ionises
ionises completely
partially ionises in water to produce an alkali that
In water to produce
in water to produce low concentration ionises completely
high concentration
low concentration of hydroxide ions, In water to produce
of hydrogen ions,
of hydrogen ions, OH-. high concentration
H+.
H+. of hydroxide ions,
OH-.
Indicator acid neutral alkali
Litmus solution RED PURPLE BLUE
Methyl orange RED ORANGE YELLOW
Phenolphthalein COLOURLESS COLOURLESS PINK
Universal RED GREEN PURPLE
indicator

4. To investigate the relationship between concentration of hydrogen ions and pH value
1.21 pH value 2.98
0.1mol dm-3 0.01mol dm-3
Hydrochloric acid Hydrochloric acid
HCl g H+ + Cl- HCl g H+ + Cl-
0.1 mol dm-3 0.1 mol dm-3 0.1 mol dm-3 0.01 mol dm-3 0.01 mol dm-3 0.01 mol dm-3
Concentration hydrogen ion in 0.1 mol dm-3
Of hydrochloric acid is higher than 0.01 mol dm-3
of hydrochloric acid.

5. Acids Bases
An acid only shows its acidic Role of water
properties when water is present.
Properties Hydrochloric acid Hydrochloric acid
in dry in water
methylbenzene
Litmus It does not
paper change the colour
of blue litmus
paper
Electrical
conductivity
Hydrochloric acid
in dry
methylbenzene

6. Acids Bases
An acid only shows its acidic Role of water
properties when water is present.
Properties Hydrochloric acid Hydrochloric acid
in dry in water
methylbenzene
Litmus It does not
paper change the colour
of blue litmus
paper
Electrical The bulb does
conductivity not lights up.
It does not
conduct electricity
Hydrochloric acid
in dry
methylbenzene

7. Acids Bases
An acid only shows its acidic Role of water
properties when water is present.
Properties Hydrochloric acid Hydrochloric acid
in dry in water
methylbenzene
Litmus It does not It turns the blue
paper change the colour litmus paper to red.
of blue litmus
paper
Electrical The bulb does
conductivity not lights up.
It does not
conduct electricity
Hydrochloric acid
in water

8. Acids Bases
An acid only shows its acidic Role of water An alkali only shows its alkalinity
properties when water is present. properties when water is present.
Properties Hydrochloric acid Hydrochloric acid
in dry in water Properties ammonia in dry ammonia in water
methylbenzene trichloromethane
Litmus It does not It turns the blue Litmus It does not
paper change the colour litmus paper to red. paper change the colour
of blue litmus of red litmus
paper paper
Electrical The bulb does The bulb lights up. Electrical
conductivity not lights up. It conducts conductivity
It does not electricity.
conduct electricity
ammonia in
Hydrochloric acid
dry
in water trichloromethane

9. Acids Bases
An acid only shows its acidic Role of water An alkali only shows its alkalinity
properties when water is present. properties when water is present.
Properties Hydrochloric acid Hydrochloric acid
in dry in water Properties ammonia in dry ammonia in water
methylbenzene trichloromethane
Litmus It does not It turns the blue Litmus It does not
paper change the colour litmus paper to red. paper change the colour
of blue litmus of red litmus
paper paper
Electrical The bulb does The bulb lights up. Electrical The bulb does
conductivity not lights up. It conducts conductivity not lights up.
It does not electricity. It does not
conduct electricity conduct electricity
Hydrochloric acid ammonia in
dry
in water
trichloromethane

10. Acids Bases
An acid only shows its acidic Role of water An alkali only shows its alkalinity
properties when water is present. properties when water is present.
Properties Hydrochloric acid Hydrochloric acid
in dry in water Properties ammonia in dry ammonia in water
methylbenzene trichloromethane
Litmus It does not It turns the blue Litmus It does not It turns the red
paper change the colour litmus paper to red. paper change the colour litmus paper to
of blue litmus of red litmus blue.
paper paper
Electrical The bulb does The bulb lights up. Electrical The bulb does
conductivity not lights up. It conducts conductivity not lights up.
It does not electricity. It does not
conduct electricity conduct electricity
Hydrochloric acid Ammonia
in water in water

11. Acids Bases
An acid only shows its acidic Role of water An alkali only shows its alkalinity
properties when water is present. properties when water is present.
Properties Hydrochloric acid Hydrochloric acid
in dry in water Properties ammonia in dry ammonia in water
methylbenzene trichloromethane
Litmus It does not It turns the blue Litmus It does not It turns the red
paper change the colour litmus paper to red. paper change the colour litmus paper to
of blue litmus of red litmus blue.
paper paper
Electrical The bulb does The bulb lights up. Electrical The bulb does The bulb lights up.
conductivity not lights up. It conducts conductivity not lights up. It conducts
It does not electricity. It does not electricity.
conduct electricity conduct electricity
Hydrochloric acid Ammonia
in water in water

12. react Acids Bases react
with with
Chemical Properties
etal
id
Mg + 2 HCl g MgCl2 + H2
HNO3 + KOH g KNO3 + H2O
lkali
HNO3 + NaOH g NaNO3 + H2O monium salt
NaOH+NH4Cl g NaCl + NH3 + H2O
Metal arbonate
H2SO4+ CaCO3g CaSO4 + CO2 + H2O
Metal xide
K2O + HCl g 2 KCl + H2O

13. Concentration of a solution Concentration
is the quantity of solute in 0.01 mol dm-3
a given volume of solution
which is usually 1 dm-3
Acids Bases
of solution. Number of mol of solute (mol)
Concentration / Molarity (mol dm-3) =
Solute Volume of solution (dm3)
a) Number of mol of solute (mol) = Molarity x Volume(dm3)
Solution Number of mol (mol) = M x V (cm3)
b)
1000
Mass of solute (g)
Concentration (g dm-3) =
Volume of solution (dm3)
Concentration = Mass of solute (g)
Molarity = Concentration
Volume of solution (dm3)
Molar mass = Number x Molar mass
of mol
Volume of solution (dm3)
Concentration = Molarity x Molar mass

14. Standard solution Standard Solution
is a solution which its
concentration is accurately
known.
Acids Bases
You are given solid sodium hidroxide. Describe the procedure
to prepare 500cm3 of 1.0 mol dm-3 sodium hidroxide solution.
[Relative atomic mass: H=1; 0=16; Na=23]
1. Calculate the mass of solute needed to give the required volume and molarity.
Number of mol, = M V (cm3) Number of mol, = Mass, NaOH
NaOH NaOH
1000 Molar mass
= 1.0 mol dm-3 (500cm3
) Mass, = Number of mol x Molar mass
1000 NaOH
= 0.5 mol = 0.5 mol x (23 + 16 +1) g mol-1
= 20.0 g
2. The solute is weighed.
20.0g Electronic Balance

15. Standard solution Standard Solution
is a solution which its
concentration is accurately
known.
Acids Bases
You are given solid sodium hidroxide. Describe the procedure
to prepare 500cm3 of 1.0 mol dm-3 sodium hidroxide solution.
[Relative atomic mass: H=1; 0=16; Na=23]
3. Dissolve the solute in distilled water in a beaker.
20.0g Sodium hydroxide
glass rod
Sodium hydroxide
Distilled water
solution

16. Standard solution Standard Solution
is a solution which its
concentration is accurately
known.
Acids Bases
You are given solid sodium hidroxide. Describe the procedure
to prepare 500cm3 of 1.0 mol dm-3 sodium hidroxide solution.
[Relative atomic mass: H=1; 0=16; Na=23]
4. Transfer the content into a 500cm3 volumetric flask.
Calibration mark
Volumetric flask
500cm3

17. Standard solution Standard Solution
is a solution which its
concentration is accurately
known.
Acids Bases
You are given solid sodium hidroxide. Describe the procedure
to prepare 500cm3 of 1.0 mol dm-3 sodium hidroxide solution.
[Relative atomic mass: H=1; 0=16; Na=23]
5. Rinse the beaker with distilled water and transfer all the content into the
volumetric flask.
Wash bottle

18. Standard solution Standard Solution
is a solution which its
concentration is accurately
known.
Acids Bases
You are given solid sodium hidroxide. Describe the procedure
to prepare 500cm3 of 1.0 mol dm-3 sodium hidroxide solution.
[Relative atomic mass: H=1; 0=16; Na=23]
6. Distilled water is added to the volumetric flask untill the calibration mark.

19. Standard solution Standard Solution
is a solution which its
concentration is accurately
known.
Acids Bases
You are given solid sodium hidroxide. Describe the procedure
to prepare 500cm3 of 1.0 mol dm-3 sodium hidroxide solution.
[Relative atomic mass: H=1; 0=16; Na=23]
7. The volumetric flask is closed tightly with stopper and inverted a few time to get
homogeneous solution.

20. Standard solution Standard Solution
is a solution which its
concentration is accurately
known.
Acids Bases
You are given solid sodium hidroxide. Describe the procedure
to prepare 500cm3 of 1.0 mol dm-3 sodium hidroxide solution.
[Relative atomic mass: H=1; 0=16; Na=23]
7. The volumetric flask is closed tightly with stopper and inverted a few time to get
homogeneous solution.

21. Standard solution Standard Solution
is a solution which its
concentration is accurately
known.
Acids Bases
You are given solid sodium hidroxide. Describe the procedure
to prepare 500cm3 of 1.0 mol dm-3 sodium hidroxide solution.
[Relative atomic mass: H=1; 0=16; Na=23]
7. The volumetric flask is closed tightly with stopper and inverted a few time to get
homogeneous solution.

22. Standard solution Standard Solution
is a solution which its
concentration is accurately
known.
Acids Bases
You are given solid sodium hidroxide. Describe the procedure
to prepare 500cm3 of 1.0 mol dm-3 sodium hidroxide solution.
[Relative atomic mass: H=1; 0=16; Na=23]
7. The volumetric flask is closed tightly with stopper and inverted a few time to get
homogeneous solution.
500 cm3 1.0 mol dm-3,
Sodium hydroxide solution

23. Dilute the solution by Dilution
adding water to the
standard solution.
Acids Bases
You are asked to dilute the standard sodium hydroxide solution
that you had made before to 250cm3 of 0.1 mol dm-3.
Describe how you would prepare the dilute solution.
1. Calculate the volume of 1.0 mol dm-3 sodium hydroxide used.
M1 V1 = M2 V2
1.0 mol dm-3 V1 = 0.1 mol dm-3 (250 cm3)
-3
V1 = 0.1 mol dm (250 cm3)
1.0 mol dm-3
= 25 cm3

24. Dilute the solution by Dilution
adding water to the
standard solution.
Acids Bases
You are asked to dilute the standard sodium hydroxide solution
that you had made before into 250cm3 of 0.1 mol dm-3.
Describe how you would prepare the dilute solution.
2. Pipette 25cm3 of 1.0 mol dm-3 sodium hidroxide solution.
25 cm3
Sodium hidroxide
pipette

25. Dilute the solution by Dilution
adding water to the
standard solution.
Acids Bases
You are asked to dilute the standard sodium hydroxide solution
that you had made before into 250cm3 of 0.1 mol dm-3.
Describe how you would prepare the dilute solution.
3. Transfer the 25 cm3 sodium hydroxide solution into 250cm3 volumetric flask.

26. Dilute the solution by Dilution
adding water to the
standard solution.
Acids Bases
You are asked to dilute the standard sodium hydroxide solution
that you had made before into 250cm3 of 0.1 mol dm-3.
Describe how you would prepare the dilute solution.
4. Distilled water is added to the volumetric flask untill the calibation mark.
Volumetric flask
500cm3

27. Dilute the solution by Dilution
adding water to the
standard solution.
Acids Bases
You are asked to dilute the standard sodium hydroxide solution
that you had made before into 250cm3 of 0.1 mol dm-3.
Describe how you would prepare the dilute solution.
5. The volumetric flask is closed tightly with stopper and inverted a few time to get
homogeneous solution.

28. Dilute the solution by Dilution
adding water to the
standard solution.
Acids Bases
You are asked to dilute the standard sodium hydroxide solution
that you had made before into 250cm3 of 0.1 mol dm-3.
Describe how you would prepare the dilute solution.
5. The volumetric flask is closed tightly with stopper and inverted a few time to get
homogeneous solution.

29. Dilute the solution by Dilution
adding water to the
standard solution.
Acids Bases
You are asked to dilute the standard sodium hydroxide solution
that you had made before into 250cm3 of 0.1 mol dm-3.
Describe how you would prepare the dilute solution.
5. The volumetric flask is closed tightly with stopper and inverted a few time to get
homogeneous solution.

30. Dilute the solution by Dilution
adding water to the
standard solution.
Acids Bases
You are asked to dilute the standard sodium hydroxide solution
that you had made before into 250cm3 of 0.1 mol dm-3.
Describe how you would prepare the dilute solution.
5. The volumetric flask is closed tightly with stopper and inverted a few time to get
homogeneous solution.
250 cm3 0.1 mol dm-3,
Sodium hydroxide solution

31. Neutralisation is the Neutralisation
reaction between an acid
and a base to form only
salt and water
Acids + Bases salt + water
An acid-base titration Daily Life
is a technique used to
determine the volume Agriculture
of an acid required
to neutralise a fixed Industries
volume of an alkali
with the help of Health
Acid-base indicator
1. An exact volume of alkali is measured with a
pipette and poured into a conical flask.
2. A few drops of indicator is added to the alkali.
acid
dropper 3. A burette is filled with an acid.
4. The acid is added drop by drop into the alkali in
the conical flask until the indicator changes colour
alkali
(indicating the pH of neutral solution produce).