EXPERIMENT -3
Aim: To Purify an impure sample of copper sulphate (CusO4. 5 H20)
Material required: 50 mL capacity Beaker, filtration unit, watch
and CuSO4. 5 H20 glass, kerosene burner
Experimental setup:
A. Procedure of crystallization of copper sulphate:
1. Prepare a clear solution of copper
2. sulphate.
Dissolve 0.8 g of CuSO4.5H,0 in about
mL H2SO4 to it. 8 mL of water and add 1-2 drops of about 6
3. Heat the
solution for a while and
4. Transfer the filter it using a filtration unit.
solution from the filtration unit to
to room temperature. another beaker and allow it to cool
5. The
6. Filter,crystals
wash
will appear.
these
7. Weigh the crystals crystals and let them
and report the yield. dry.
Watch glass
50 ml Beaker
30
90
Tripod
Kerosene bumer
Result: the quantity of
pure sample of
Precautions: copper sulphate
Ensure that the obtained is = 0.5 g
Avoid crystals are washed well.
The
overheating
The filtrate of
be
the
should solution.
solution should beevaporat
cooled ed slowly by gentle
slowly and do not useheating of the
any rapid solution.
cooling
Aim: To Purify an EXPERIMENT -4
impure sample of Alum
Material
and Alumrequired: mL capacity Beaker,
50
filtration unit, watch glass,
kerosene burner
Experimental setup:
A.
Procedure of crystallization of Alum:
1. First, prepare a clear
mL of water. solution of alum by dissolving 1g of
2.. To this Alum sample in about 5
3. Heat thesolution add 2 drops of H>SO4.
4. solution fora while and filter it using a
Transfer the solution from the filtration unit to filtration unit.
5.
down to room
temperature. another beaker and allow it to cool
6.
Formation the crystals is witnessed.
of
Filter and wash these crystals and
7. allow them to dry.
Weigh the crystals and report the yield.
Watch glass
50 ml Beaker
40
30
20
Tripod
-Kerosene burner
Result: the quantity of pure sample of Alum obtained is = 0.8 g
Precautions:
Ensure that the crystals are washed well.
Avoid overheating of the solution.
The filtrate should be evaporated slowly by gentle heating of the solution.
The solution should be cooled slowly and do not use any rapid cooling procedures
EXPERIMENT-5
Aim: Determination of pH of Solutions like fruit juices of diferent acids, bases, and salts
using universal indicator.
Material required: Universal indicator, sample solutions, test tubes, white tile and
dropper
Procedure of determination of PH using universal indicator:
1. Take the given samples of fruit juices like lemon, orange, pineapple, and apple in a
separate test tube.
2. Make sure you have taken at least 2 ml of juices in each test tube.
3. Use a separate dropper to transfer each juice sample into a test tube.
4. Add two drops of universal indicator.
5. Mix the content thoroughly by shaking it gently.
6. Refer the pH chart to match the colour that appears in the test tube. (match the
colour produced with standard colour pH chart)
7. Record your observation
Observation:
Determination of pH Using Universal Indicator on different samples of fruit juice
Sample Colour with pH indicator pH inference
Apple juice red colour 3-4 Moderate acidic
Pineapple juice Orange red 2-3 Strong acidic
Orange juice Orange 4-5 Moderate acidic
Lemon juice Yellowish orange 2-3 Strong acidic
Procedure:
Carefully match the colour of the solution that appears with the standard colour
pH chart.
Add the equal quantity of indicator into the juice sample
EXPERIMENT-6
Aim: To compare the pH of solutions of strong and weak acids of the same concentration -
hydrochloric acid (HCI) and acetic acid (CH3COOH).
Material required: 0.1M HCI, 0.01M HCI, 0.001M HCI, 0.0001 M HCI, and 0.00001M HCI
test tubes, glass rod, and universal indicator.
Procedure of determination of PH using universal indicator:
1. Take 2-3 drops of solutions of the given concentration on pH paper with the help of
glass rod.
2. Observe the change in colour of the pH paper
3. Match the shade of the pH paper with standard pH indicator chart.
4. Note the approximate pH of the sample
Observation:
Determination of pH Using Universal Indicator on different samples of fruit juice
Sample Colour with pH Approximate pH=- log[H]
indicator pH
0.1M HCI Red 1-2 1
0.01M HCI Orange red 2-3 2
0.001M HCI Orange 3-4 3
0.0001M HCI Orange 4-5 4
Procedure:
" Ensure to handle the test tube carefully.
" Do not add more indicator.
" Keep the pH paper clean.
" Compare the colour of the solution in the test tube and pH paper colour exactly
with the standard pH indicator chart.
EXPERIMENT - 7
determine the molarity of the given solution of sodium hydroxide (NaOH) by
Aim: To (0.05M) oxalic acid.
titrating it against standard solution of
burette stand, white porcelain tile, etc.
Apparatus Required: Burette, pipette, conical flask,Oxalic acid, NaOH solution,
Chemical Required: Standard solution of (0.05 M))
phenolphthalein indicator.
titration is in between weak acid
Theory: This is an alkalimetry type of titration. The
(H2C204.2H;0) and strong base (NaOH)
(COOH), +2NaOH’ (COONa), + 2H,0
Indicator: phenolphthalein
End point: colourless to light pink
Observations: -
1. Preparation of standard solution: -
Weight of empty water glass (W1) = 21.7200 g
Weight of watch glass + Mohr's salt (w2) = 23.2950 g
Weight of oxalic acid =w2- W1 =(23.2950 - 21.7200) g = 1.575 g
Volume of oxalic acid = 250 ml
Volume of oxalic acid taken for each titration (V2) = 20 ml
2. Titration of standard solution with NaOH Solution:
Observation Table:
S.N. Volume of oxalic Burette reading Volume of
acid used (Vi ml) NaOH used Concordant
Initial Final
Volume (V2)
1 20 ml 0.0 16.8 16.8 ml
2. 20 ml 0.0 16.6 16.6 ml 16.6 ml
3 20 ml 0.0 16.6 16.6 ml
Calculations:
1. determination of molarity of NaOH solution:
M1= molarity of NaOH soln =?
2 moles of NaOH requires 1 moles of oxalic acid V= volume of NaOH solr= 14.6 ml
Mz = molarity of oxalic acid = M/50
MiVi= 2 MAV2 V2 volume of oxalic acid= 20 ml
MiVi =2 MVz
M1x 16.6= 2 x M/20 x20
M)=0.120 M.
2. determination of strength of NaOH
solution
Strength = Molarity y Molr hdas
Result: 1. Molarity of the given solution =0.120 M.
2. Strength of the given solution =4.80 g/lite.
Precaution:
Wash the burette with water before and after titration is over.
Wash the watch glass carefully so that there is no crystal left on the watch glass.
The last few drops should be added using a pipette to avoid any extra addition of
distilled water above the mark on the neck.
EXPERIMENT - 8
(HCI) solution by using a
Aim: To determine the molarity of the given hydrochloric acid
standard solution of (0.05M) sodium carbonate (Na,COs).
Apparatus Required: Burette, comical flask, pipette, burette stand, test tube, white tile,
watch glass, volumetric flask (250ml) beaker, funnel glass rod, weight box, wash bottle.
Chemical Required: Standard solution of (0.05 M) NazcO3, HCI solution, methyl orange
indicator.
weak
Theory: This is an acidimetry titration. The titration is between strong add (HCI) and
base (Na,CO3).
Molecular equation:
NazCOx) + 2 HCIag ’2 NaClag +COzlg) + H20o
Indicator: Methyl orange
End point: yellow to pink
Observations: -
1. Solution in a burette: Hydrochloric acid solution
2. Solution by a pipette: sodium carbonate solution
Observation Table:
S.N. Volume of sodium Burette reading Volume of
HCl used Concordant
Carbonate used (Vi Initial Final
ml) Volume (V:)
1. 10 ml 0.0 9.9 9.9 ml
2. 10 ml 0.0 9.7 9.7 ml 9.7 ml
3. 10 ml 0.0 9.7 9.7 ml
Calculations:
1. determination of molarity of HCl solution:
1 mole of NazCO, requires 2 moles of HCI M= molarity of HCIi sol =?
VË= volume of HCI soln = 9.7 ml
2 M,V) = M,V2
M2 = molarity of Na2CO3 soln= M/20
MiV1 = 1/2 M2V2 V2= volume of Na2CO, sol" = 10 ml
MË X9.7 = 1/2 x 0.05 x10
M2=0.025 M
2. determination of strength of KMNO4 solution
Strength= Molarity x Molar Mass
= 0.025x 36.5 = 0.9125 g/liter.
Result: 1. Molarity of the given solution = 0.025 M.
2. Strength of the given solution =0.9125 g/liter.
Precaution:
" While weighing does not spill the substance on balance pan.
Rotate the knob of balance gently.
" Keep the weights in weights box at proper places after weighing
" Wash the watch glass carefully so that even a single crystal is not left on the
watch glass.
" Bring the watch glass close to funnel while transferring weighed substance and
transfer it gently. Wash it repeatedly with distilled water.
" Wash the burette with water after titration is over.
Last few drops should be added using pipette to avoid extra addition of
distilled water above the mark on the neck of the measuring cylinder.
