Detailed description of the process of Reaction of Baking Soda and Vinegar and Testing Carbon Dioxide with Lime water

1. CHEMICAL CHANGES
PART – 3
Grade: 7
Subject: SCIENCE
CH – 6 Physical and Chemical changes

2. BAKING SODA
• Baking Soda or Sodium bicarbonate is a white
solid that is found as crystal or as a fine
powder. It is a Basic Compound.
• Chemically it is called Sodium Hydrogen
Carbonate and the chemical formula NaHCO3.
• Mostly used for baking.

3. VINEGAR
• Vinegar is an aqueous solution of acetic
acid (CH3COOH) and trace substances that may
include flavorings.
• It is acidic in nature and has a sour taste. It is a
weak acid.
• It is mainly used for Pickles, as preservatives and
for household cleaning.
• The source materials for making vinegar are
varied: different fruits, grains, and
other fermentable materials are used. For eg.
Fruit Vinegar, Palm vinegar, Balsamic Vinegar etc.

4. REACTION OF BAKING SODA AND
VINEGAR
• If we add a pinch of baking soda to a
teaspoonful of vinegar, we would hear a
hissing sound.
• We also see bubbles of a gas coming out.
• This is a vigorous reaction.

5. IMPORTANT REACTIONS
• Vinegar (Acetic acid) + Baking soda (Sodium
hydrogen carbonate) → Carbon dioxide + other
substances
• This is a Chemical Change as Carbon Dioxide is
given off and new substances are formed.
• This method is sometimes used in baking as the
Carbon dioxide released in the process makes
the dough rise and makes the bread spongy.

6. HOW DO WE TEST THAT THE GAS
RELEASED IS CARBON DIOXIDE?
• There is chemical called
Lime Water (Its not Lemon
water or lemonade).
Limewater is the common
name for a aqueous
solution of calcium
hydroxide (Ca(OH)2 ).
• Limewater is clear and
colorless, with a slight
earthy smell and an bitter
taste suggesting it is a
base.
• On passing Carbon Dioxide
through this solution, it
becomes Milky. (White like
milk)
Vinegar +
Baking
soda
CO2
LIME
WATER

7. IMPORTANT REACTIONS
• Carbon dioxide (CO2) + Lime water [Ca(OH)2]
→ Calcium Carbonate (CaCO3) + Water (H2O)
(milky)
It is also a Chemical Change.
A new substance-Calcium Carbonate
Is formed.
• It is a common experiment to test which gas is
given during exhalation.