Fun Video: Properties of Acids and Bases Video Lecture - Class 10

Properties of Acids and Bases
Reaction of HCl with litmus solutions
We require two test tubes placed in a test
tube rack, red and blue litmus solutions,
HCl solution and a dropper.
Take the red litmus solution.
Pour the red litmus solution into a test tube.
Re-cap the bottle.
Take the blue litmus solution.
Pour the blue litmus solution into another
test tube.
Re-cap the bottle.
Take a few drops of the HCl solution from
its bottle using a dropper.
Add this to the test tube containing the red
litmus solution.
The colour of the solution remains the same.
Again, take a few drops of the HCl solution
from its bottle using the dropper.
Add this to the test tube containing the blue
litmus solution and note the change in colour.
The colour of the solution changes from blue
to red.
HCl is an acid having pH value below 7.
Reaction of NaOH with litmus solutions
We require two test tubes placed in a test
tube rack, red and blue litmus solutions,
NaOH solution and a dropper.
Take the red litmus solution.
Pour the red litmus solution into a test tube.
Re-cap the bottle.
Take the blue litmus solution.
Pour the blue litmus solution into the other
test tube.
Re-cap the bottle.
Take few drops of the NaOH solution from its
bottle using the dropper.
Add this to the test tube containing the red
litmus solution and note the change in colour.
The colour of the solution changes from red
to blue.
NaOH is an alkali having pH more than 7.
Again take few drops of the NaOH solution
from its bottle using the dropper.
Now, add it to the test tube containing the
blue litmus solution.
The colour of the solution remains the same.
Reaction of HCl with zinc metal
We require a test tube, a small piece of zinc
metal in a dish, a spatula, HCl Solution,
a dropper, a stand with a clamp, a single
bored cork, a jet tube, Bunsen burner and
a match box.
Using the spatula transfer some of the zinc
metal from the dish into the test tube.
Take few drops of the HCl solution from its
bottle using the dropper.
Add this to the test tube containing the zinc
metal.
Clamp the test tube to the stand, then close
the mouth of the test tube with the cork and
pass the jet tube through the hole in the
cork, into the test tube.
Now, bring the clamped test tube downwards
to heat it over the Bunsen burner.
Hydrogen gas is evolved on heating.
Take the match box and light a match stick.
Bring the burning match near to the mouth
of the jet tube.
Hydrogen gas coming out of the test tube causes
the flame to flare up.
Then, with a mild explosion and producing
a popping sound, the flame dips out.
Reaction of NaOH with zinc metal
We require a test tube, some zinc metal in
a dish, a spatula, NaOH Solution, a dropper,
a stand with a clamp, a single bored cork,
a jet tube, Bunsen burner and a match box.
Using the spatula, transfer some of the zinc
metal from the dish into the test tube.
Take few drops of the NaOH solution from its
bottle using the dropper.
Add this to the test tube containing the zinc
metal.
Clamp the test tube to the stand, then close
the mouth of the test tube with the cork and
pass the jet tube through the hole in the
cork, into the test tube.
Now, bring the clamped test tube downwards
to heat it over the Bunsen burner.
Hydrogen gas is evolved on heating.
Take the match box and light a match stick.
Bring the lighted match near the mouth of
the jet tube.
Hydrogen gas coming out of the test tube causes
the flame to flare up.
Then, with a mild explosion and producing
a popping sound, the flame dips out.
Reaction of HCl with solid sodium carbonate
We require a flat bottom flask, a stand, a
thistle funnel, a connecting glass tube, distilled
water in a beaker, a stand with a clamp, some
sodium carbonate in a dish, double bored cork,
spatula, HCl solution, a dropper and lime
water in a beaker.
Place the flat bottom flask on the clamp stand
and clamp the neck of the flask.
Using the spatula, take some Sodium Carbonate
from the dish.
Put this into the flat bottom flask.
Take the beaker containing the distilled water.
Pour some of it into the flat bottom flask.
Cork the flask with the double bored cork
and insert the thistle funnel into the flask
through one of the holes in the cork.
Take the beaker containing lime water.
Place this on the other stand next to the
flat bottom flask.
Carefully insert one end of the connecting
tube into the flat bottom flask through the
hole in the cork.
Ensure the tube does not touch the solution
in the flask.
Place the other end of the tube in the beaker
containing lime water.
Take the bottle containing the solution of
HCl.
Pour some of it through the thistle funnel
into the flat bottom flask.
A gas is evolved.
You will note that the lime water in the beaker
has turned milky.
Thus, the gas evolved is CO2 which turns lime
water milky.
Reaction of NaOH with solid sodium carbonate
We require a test tube, a test tube rack,
some sodium carbonate in a dish, a spatula,
NaOH solution, and Phenolphthalein solution.
Take the test tube.
Using the spatula take some Sodium Carbonate
from the dish.
Transfer the contents into the test tube.
Take the solution of NaOH.
Pour some of it into the test tube.
Shake the test tube well.
Take few drops of Phenolphthalein from the
bottle using the dropper.
Pour a few drops into the test tube and note
the change in colour.
The colour of the solution turns pink.
Both Na2CO3 and NaOH are alkalis, so they
do not react but form alkaline sol.
Phenolphthalein produces a pink colour in
alkaline medium.