by Dilip Kumar Chandra PGT Biotechnology JNV Raipur CG

2.  Substances taste sour contain acids.
Examples
LEMON ------ CITRIC ACID
TAMARIND ------ TARTARIC ACID
TOMATOES ------ CITRIC ACID
APPLE ----- MALEIC ACID
VINEGAR ------ ACETIC ACID
ANTS ------ FORMIC ACID
CURD ------ LACTIC ACID

3.  OTHER EXAMPLES OF ACIDS USED
IN LAB----
 1.HYDROCHLORIC ACID (HCl)
 2.SULPHURIC ACID(H2SO4)
 3.NITRIC ACID(HNO3)
 4.PHOSPHORIC ACID(H3PO4)
 5.ACETIC ACID(CH3COOH)

4.  THEY ARE SOUR TO TASTE.
 THEY TURN BLUE LITMUS PAPER TO
RED.
 THEY REACT WITH BASES TO FORM
SALT AND WATER.

5.  S + O2 SO2
Sulphur Oxygen
Sulphurdioxide
 H2O + SO2 H2SO3
Water sulphurous
acid
 When non metallic oxides are
dissolved in water acids are formed.

6.  Substances which are bitter in taste and
soapy to touch are known as Bases.
NAME OF THE BASE FOUND IN
Calcium hydroxide
Ammonium hydroxide
Sodium/potassium
hydroxide
Magnesium hydroxide
Lemon water
Window cleaner
Soap
Milk of magnesia

7. GENERAL PROPERTIES OF BASES
 THEY ARE BITTER TO TASTE AND
SOAPY TO TOUCH.
 THEY TURN RED LITMUS PAPER TO
BLUE.
 THEY REACT WITH ACIDS TO FORM
SALT AND WATER.

8. PREPARATION OF BASES
When metallic oxides are dissolved in
water Bases are formed.
2Mg + O2  2MgO
Magnesium Oxide
MgO + H2O  Mg(OH)2
Magnesium Hydroxide

9.  Solutions of substances that show
different colour in acidic, basic and
neutral solutions are called indicators
litmus

10.  LITMUS
 The most commonly used natural
indicator. It is extracted from
Lichens.It has a purple colour .when
added to acid it turns red.When
added to basic it turns blue.
Acid litmus
Base litmus

11.  CHINA ROSE INDICATOR.
 China rose indicator turns dark pink
to acidic solution
 China rose indicator turns green to
basic solution

12.  Neutralization is the process of
adding right amount of acid to base
or base to acid, a neutral solution
is obtained, which is neither an
acid nor a base.

13. HOW CAN WE VERIFY THE
NEUTRALIZATION REACTION?
 To verify neutralization reaction let us
conduct an activity/demonstration.
STEP -1
 Take a test tube and fill ¼ th of
test tube with dil.NaOH . Which
is colourless.
Titrant
Titrated

14.  Add 2-3 drops of phenolphthalein
indicator.
 Solution turns pink. [phenolphthalein
give pink colour only in basic medium
but not in acidic medium]

15.  Step-2.Solution turns pink. [phenolphthalein
give pink colour only in basic medium but not
in acidic medium]
 Step-3. Add dil Hcl drop by drop to the test
tube with the help of dropper till the pink just
disappear.

16. .
Step-4. Add dil Hcl drop by drop to the test tube
with the help of dropper till the pink just
disappear.
 Step-5.The colouless solution which is
obtained is a neutral solution.

18. WHAT HAPPENS WHEN WE ARE
SUFFERING FROM ACIDITY ?
 we suffer from indigestion
 , stomach pain and ulcer.
 what is the remedy?
 we use an antacid, such as
milk of magnesia
{magnesium hydroxide}
it neutralizes excessive acid.

19. WHAT HAPPENS WHEN AN ANT BITES ?
 Ant inject formic acid which
cause severe irritation, pain and
burning sensation.
 What is the remedy?
 We apply sodium bicarbonate or
calamine solution to neutralize
effect of formic acid.

20. WHAT HAPPENS WHEN WE USE EXTENSIVE
CHEMICAL FERTILIZERS IN THE
AGRICULTURAL LAND ?
 After the extensive use of chemical
fertilizer the acidy of soil will be
more.
 What is the remedy?
 In order to neutralize
acidity of soil we add
Calcium hydroxide to soil.