Transcript Chemistry Project: Acids and alkalis

Chemistry Project:
Acids and alkalis
The aim of the
project:
To know more
the details of
alkalis and acids.
Other details
Experiment
Results
Web Site ‘s version
Group member






Lee Keng Ho (21)
Lee Ho (20)
Lam Chung Wai (14)
Wong Kin Sang (38)
Chan Shing Ho (6)
LAM Ka Shing (16)
What is soil?

Involves many nutrients and nature
chemicals.

To provide the nutrients for helping
grow plants.
Experiment 1: Testing the soil





~ beaker (-to store
the water and soil to
test the alkalis and
acids)
~ glass rod (use to stir
the liquid)
~ soil (main substance
in the experiment)
~ water (to dissolve
the acids by the soil)
~ pH paper (test the
alkalis and acids)
Experiment 1: Testing the soil






Step 1:
Drop some soil in to the beaker.
Step 2:
Use the glass rod to stir the soil
and water in the beaker.
Step 3:
Put pH paper into the beaker to
test the alkalis and acids.
Experiment 1: Testing the soil

The figure of making
the experiment .
Experiment 1: Testing the soil



Results:
The pH value of the soil is :
That means the soil ia neutral state.
 The ph colour is orange.
Experiment 1: Testing the soil

Main Details Of Acids Base: pH paper

pH
pH
pH
pH
pH




1 ~ very strong acids
2-6 ~ weak acids
7 ~ neutral
8-13 ~ weak alkali
14 ~ very strong alkali
What is the main use of fertilizer

(1) Be a refractory material.

(2) Be nutrient in plant.

(3) Be an additive into the forage of domestic
animal.

(4).Used to prevent fire with paper nad wooden
things.
What is the advantage of fertilizer?

To Get a good condition in soil to let plants grow
it’s best!

To recruit the leakage of the soil.
What is the weaknesses of fertilizer?

Make dirty in water.

Some of chemicals may damage the sir.
Experiment 2: Making fertilizer

Procedure:






Step 1:
Place about 10cm of ammonia solution in a
conical flask.
Step 2:
Add 2-3 drops of indicator solution
( methyl orange)./ Add pH paper
Step 3:
Fill a burette with a sulphuric acid.
Experiment 2: Making fertilizer

Procedure:






Step 4:
Slowly add the acid to the conical flask
until the indicator changes colour from
yellow to red.(if we use the pH paper , it
changes colour from blue to red )
Step 5:
Repeat, using the same volumes of alkali
and acid but without any indicator .
Step 6:
Place some of the neutral solution in the
evaporating basin. Heat gently to
evaporate the solution.
Experiment 2: Making fertilizer

Procedure:


Step 7:
Collect the solid into the test tube.
Experiment 2: Making fertilizer

Results:

The apperance of fertilizer is prersent.
It ‘s a white solid.
Experiment 3: Extraction and
separation of leaf pigments by
paper chromatography




apparatus:
Plant material ( the leaves of your growing plant)
Extraction solvent (acetone / petroleum) 1:1
Developing solvent (acetone / petroleum) 1:9
Experiment 3: Extraction and
separation of leaf pigments by
paper chromatography




Step 1:
Prepare strips of chromatography paper of
the right width so that each can be hung
freely in a boiling tube without touching
the wall. The length of the paper should be
trimmed according to the level of solvent
to be put into each boiling tube.
Step 2:
mark an origin for spotting on the paper
about 2cm from the lower edge of the
paper.
Experiment 3: Extraction and
separation of leaf pigments by
paper chromatography




Step 3:
Transfer appropriate amount of the
developing solvent into the boiling tube ( a
depth of not more than 1.5cm ). Stopper
them for equilibrium.
Step 4:
preparation of pigment extract:



.Wash leaves and blot dry.
.Cut leaves into small segments and put into a
mortar.
.Grind the tissue in the extraction solvent
with a pestle to extract the pigments.
Experiment 3: Extraction and
separation of leaf pigments by
paper chromatography




Step 5:
By means of a capillary tube spot the
extract onto the origin marked on the
paper strip and allow it to dry.
Step 6:
Repeat the spotting and drying processes
obtain a small area of concentrated leaf
extract.
Experiment 3: Extraction and
separation of leaf pigments by
paper chromatography




Step 7:
Pin the paper onto the lower surface of the
cork and insert the paper into the boiling
tube. The solvent should cover the lower
end of the paper but without touching the
spot.
Step 8:
Allow the chromatogram to develop until
the solvent front has moved up for 10cm or
more.
Experiment 3: Extraction and
separation of leaf pigments by
paper chromatography
Step 9:
 Take out the chromatogram, mark the
solvent front and allow the chromatogram
to dry in air.
 Step 10:
 Use pencil to circle each spot.
 Step 11:
 Identify the pigments by their colors on the
chromatogram.

Experiment 3: Extraction and
separation of leaf pigments by
paper chromatography

Results:

The color of pigments change from yellow to
pale green.
Question:

Are there any other way to test acids?

hair
________

Web Site of our Project:

http://www.angelfire.com/electronic/chemist
ry1/index1.html