Try Yourself
1. Crystalline CsBr has bcc structure. Calculate the unit cell edge length, if the
density of CsBr crystals is 4.24 g cm-3.
2. A crystal of Lead ‘II’ sulphide has NaCl structure . In this crystal the shortest
distance between Pb2+ ion and a S2- ion is 297 pm. What is the length of edge of
unit cell in Lead sulphide ? Also calculate the unit cell volume.
3. Calculate the value of Avogadro’s number from the following data.
Density of NaCl = 2.165 g cm-3
Distance between Na+ and Cl- in NaCl = 281 pm
4. The compound CuCl has ZnS (cubic) structure. Its edge length is 500 pm. Find
density.
5. CsCl has body centered cubic lattice length of a side of unit cell 412.1 pm and
Aluminium in fcc lattice with length of the side of unit cell 405 pm. Which of the
two has larger density
6. CsCl has cubic structure. Its density is 3.99 g cm-3 .What is the distance
between Cs+ and Cl- ?
7. Lead (II) sulphide has NaCl structure. What is the distance between Pb 2+ and
S2- ions in PbS, if its density is 12.7 g cm-3 ?
8. KBr has Fcc structure. The density of KBr is 2.75 g cm-3. Find the distance
between K+ and Br- ?
LAB MANUAL
ENGINEERING CHEMISTRY
Estd.2006
Prepared by
Dr. WAJIUL HASSAN RIZVI
Head, Department of Engineering Chemistry
DEPARTMENT
CHEMISTRY
OF ENGINEERING
JAGADGURU DATTATRAY COLLEGE OF
TECHNOLOGY
Campus, Vill.-Sinhasa, Sinhasa, Jawahar Tekari , Dhar Road, Indore - 452002 (M.P.)
Phone : 0731-3016405,
Fax No : 0731-2892311
Email : jdct_chem@rediffmail.
OBJECTIVE OF EXPERIMENT
EXPT.No
Determination of total hardness of given water sample
by Complexometric method using N/50 EDTA.
1
PAGE
NO.
2
3
4
5
6
7
8
9
10
11
12
Determination of total hardness of given sample of
water byComplexometric method by using disodium salt
of EDTA solution
Determination of Alkalinity of given water sample(1) by
using N/50 HCL as a intermediate solution
Determination of Alkalinity of given water sample (2)by
using N/50 HCL as a intermediate solution.
Chloride ion estimation by Argentometric method .
Determination of flash point of an oil using Clevland
open–cup Apparatus
Determination of flash point of an oil using PenskyMarten closed-cup Apparatus
Determination of flash point of an oil using Abel’s closed
–cup Apparatus
Determination of viscosity index of lubricant oil by
Redwood Viscometer No-1
Determination of viscosity index of lubricant oil by
Redwood ViscometerNo-2
Determination of moisture content of coal sample using
Hot Oven
Determination ofvolatile content of coal sample using
Muffle Furnace
JAGADGURU DATTATRAY COLLEGE OF TECHNOLOGY
ENGINEERING CHEMISTRY LAB
EXPERIMENTNo–
1
Date of conduction:
/
/ 20….
Date of submission:
/
/ 20….
OBJECTIVE: Determination of total hardness of given sample of water
by Complexometric method using given N/50 EDTA solution
Apparatus and Reagent Required:
Burette, Pipette, Conical Flask, Beaker, , Funnel, Test Tube, Burette Stand.
EDTA Sol., Black-T etc.
Theory: Ethylene Diamine Tetra Acetic (EDTA) is a well known complexing
agent, which is widely used in analytical work. On account of its powerful
complexing action and commercial availability. This also available under trade
names as Versene or Tritriplex III. Its chemical formula can be represented in
fig.(i).
The spatial structure of its anion which has six donor atoms, enables it to satisfy
the coordination no. of six frequently encounted among the metal ions and to form
stainless five-membered rings on chelation.
EDTA form complex with Ca2+ and Mg2+ as well as with many other metals
cations, in aqueous solution. These have the general formula as shown in fig.(ii)
7
Where
M2+ = Ca2+, Mg2+, etc.
EDTA is generally used in the form of disodium salt or tetra-sodium salt on
account of their greater solubility. If simplicity of discussion EDTA is assigned
the formula H2Y2- the sodium salt will be Na2H2Y which gives the complex
forming ions H2Y2- in aqueous solution. Its reactivity with metal ions is a 1:1. The
reaction with divalent cations, M2+ (such as Ca2+ and Mg2+) may be represented as
M2+ + H2Y2-  MY- + 2H+
Similarly, with trivalent and tetra cations, the reactions may be expressed as
M3+ +
H2Y2-  MY- + 2H+
M4+ +
H2Y2-  MY+ + 2H+
Mn+1 =
H2Y2-  MY(n-4) + 2H+
Thus, it is evident that 1mole of the complex forming H2Y2- reacts in all cases
with none mole of the metal ion and also. In each case two mole of hydrogen ion
are generated.
Stability of some metals EDTA Complexes with respect to pH
METAL IONS
Ca2+,
Mg2+,
Ba2+,
Sr2+
Cu2+, Pb2+, Zn2+, Co2+, Ni2+, Mn2+, Fe2+,
Al3+, Cd2+
Zn4+, Hf4+, Th4+, Br3+, Fe3+
Minimum pH of which
their respective
EDTA complex Exist
8-10
4-6
1-3
Eriochrome black T (EBT) is the metal-ion indicator used in the determination of
hardness by complexometric titration with EDTA. EBT is sodium-1-(1-hydroxy’2-naphthyl azo)-6-nitro-2-naphthol-4-sulfonate (II) :
8
9
STRUCTURE OF ERICHROME BLACKT
Procedure:
1. Fill up burette with given N/50 EDTA solution up to mark after rinsing burette with the
same solution of EDTA.
2. Take 20ml of sample water by pipette in a 250ml conical and add nearly 2ml
Buffer solution in it
3. Now add 2-3 drops of EBT solution indicator in sample water that you have taken in
conical flask when the colour water changes to wine red
4. Now run down EDTA solution from burette drop wise carefully till the colour of water
solution changes from wine red to blue permanently and stop running EDTA solution
further . Note down the reading of burettei.e, the volume of EDTA solution. Do this
experiment 3-4 times and take out average reading of EDTA solution
CALCULATION :
Table-1
S. No.
Volume of Water
Volume of N/50 EDTA sol. (in
ml)
Sample taken
1
20mL
Vi
2
20mL
Vii
3
20mL
viii
Average reading of burette = ( Vi+ Vii+Viii)/3=V2ml
Now apply law of equivalence i.e,
V1N1 = V2N2
V1= volume of sample water , N1= normality of water to be known
V2 = volume of N/50 EDTA solution & N2 = Normality of EDTA solution
N1 = V2N2/ V1 =( N 50) x (V220) = (50000/50) x (V220)= 50 V2mg/lit
Total hardness of given sample of water = 50 V2mg/lit CaCO3equivalent
=
50 V2 PPm CaCO3equivalent
NOTE: 1N CaCO3equivalent means 50gram calcium carbonate per liter of water
or 50000mg per liter of water
RESULT:Total hardness of sample water =………PPm CaCO3equivalent
QUESTIONS
1.Why Buffer solution is used?
2.Can EDTA be used as water softener reagent? Explain
3.What is difference b/w coordination and chelation ?
4.Why hardness is always measures in terms of calcium carbonate equivalent ?
5 Write other unit of hardness and give relation among them.
JAGADGURU DATTATRAY COLLEGE OF TECHNOLOGY
ENGINEERING CHEMISTRY LAB
EXPERIMENT No -2
Date of conduction:
/
/ 20….
Date of submission:
/
/ 20….
OBJECTIVE: Determination of total hardness of given sample of water by Complexometric
titration method using Disodium salt of EDTA solution.
Apparatus and Reagent Required
Burette, Pipette, Conical Flask, Beaker, Funnel, Test Tube, Burette Stand. EDTA
Sol., Black-T,
Theory: Di sodium salt of Ethylene diamine tetra acetic acid (EDTA) is a well
known complexing agent, which is widely used in analytical work.
EDTA form complex with Ca2+ and Mg2+ as well as with many other metals
cations, in aqueous solution in 1:1 ratio whatever the charges a cations may have .
These have the general formula as shown in fig. below
In order to determine the equivalence point an indicator eriochrome black-T or EBT is
employed, which form unstable wine-red complex with Cu2+ and Mg2+ ions nearly at PH= 10
M++ + EBT
PH=10
M EBT complex
Blue colour
Wine red
Where M++ = Ca+2 , Mg+2etc
So, initially a wine-red coloured is obtained. During the course of titration against EDTA
solution, EDTA combines with M2+ (or Ca2+ or Mg2+) ions from stable complex, M-EDTA and
releasing free EBT, which instantly combines with M2+ ions, still present in the solution, thereby
wine-red colour is retained. Thus:
However, when nearly all M2+ (Ca2+ or Mg2+) ions have formed [M-EDTA]
complex, then next drop of EDTA added displaces the EBT indicator form [MEBT] complex and the wine-red colour changes to blue colour (due to EBT).
Thus, at equivalence point.
STRUCTURE OF ERICHROME BLACK-T
PROCEDURE
1.EDTA is first standardize with help of standard hard water which in turn
prepared by dissolving 1gm pure CaCO3 in 1000 ml distilled water through
HCl.EDTA is not a primary standard.
2. Now first rinse the burette with std. EDTA solution completely and fill burette
with the EDTA soln .up to mark.
3. Now pipette out 25ml of tap water or unknown hard water which is given to
you in a 250 ml conical flask .
4. Add few drops of buffer solution to sample hard water that you have taken in
conical flask to maintain and make PH of the hard water up to 10 where both EBT
and Disodium salt of EDTA work effective .
5.Now add 2-3 drops of EBT solution provided you with help of dropper and
You shall find the colour of the solution of conical flask be wine red.
6.Now run EDTA solution from burette drop wise carefully and simultaneously
shake the conical flask slowly till the colour of the solution in conical flask
changes from wine red to sky blue permanently .As soon as color changes from
wine red to blue stop running EDTA solution quickly and note down the reading
of the
burette i.e, the volume of EDTA solution consumed.
Repeat the same experiment 3 to 4 times to have an accurate measurement.
CALCULATION :Table-1
S.No. Volume of Standard
Hard Water
Sample taken
Volume of EDTA sol. (in mL)
run down (For Standardization of
EDTA)
V1
1
25mL
2
25mL
3
25mL
Table-2
S.No.
Volume of Water
Sample taken
Volume of EDTA sol. (in mL)
run down (For Total Hardness)
V2
1
25mL
2
25mL
3
25mL
Calculation:
Now, V1 ml of EDTA solution = 25x 1mg CaCO3 eq.
( 1ml = 1mg )
1 ml of EDTA solution = 25/v1 mg CaCO3 eq.
Again, 25 ml of unknown hard water has hardness = V2 ml of EDTA
solution
=
,, ,,
,,
=V2 x 25/V1 mg
CaCO3 eq.
Hence, 1ml of unknown hard water has hardness=1/25xV2x 25/V1 mg CaCO3 eq
unknown hard water has hardness =
V2 /V1 mg CaCO3 eq .
1ml of
So,1000 1ml of unknown hard water has hardness = 1000 V2/V1 mg/Lit CaCO3eq
Where, V1is the volume of EDTAsolution consumed with standard hard water and V2 is
the volume of EDTA solution consumed with unknown hard water.
RESULT : The total hardness of sample of water is …………mg/lit (or PPm)
As
1 mg /lit = 1PPm
QUESTIONS
1. Why EDTA Take up Hardness causing ions from EBT at last ?
2. Write the formula of disodium salt of EDTA
3. Why disodium salt of EDTA is used instead of simple EDTA.
JAGADGURU DATTATRAY COLLEGE OF TECHNOLOGY
ENGINEERING CHEMISTRY LAB
EXPERIMENT No – 3
Objective: Determination of alkalinity of a given water sample (1)using
N/50 HCL as a intermediate solution .
Apparatus Required: Burette, Pipette, Conical Flask, Beaker, Test Tube, Burette
Stand.
Reagent required : N/50 HCl solution , alkaline water , phenolphthalein
indicator and
methyl orange indicator etc
Some Basic Defination : Alkanility ofwater can be defined as the capacity to neutralize acid
Alkalinity of natural water may be attributed to the presence of salt of weak acid such as
bicarbonate, phosphate, silicates and water treated by lime soda process may contain
considerable quantities of carbonate & hydroxide alkalinity.
Theory : The alkalinity of water can be considered to be mainly due to the presence of the
following ions
i.
ii.
iii.
iv.
v.
Hydroxides (OH)
Carbonates (CO32)
Bicarbonates (H CO3)
Hydroxide & Carbonates (OH+ CO32)
Bicarbonates &Carbonates (H CO3+ CO3
Phenolphthalein Indicator
(works at PH range b/w 8.3 to 10.0
)
Methyl Orange Indicator (works at PH range b/w 3.1 to 4.4 )
Procedure: 1. First rinse the burette with the given solution of HCl and fill it up
to mark
2. Pipette out 20 or 25 ml of sample alkaline water in a 250ml
conical flask .
3. Add 2-3 drop of phenolphthalein by dropper in alkaline
sample water and observe colour of the solution
4. Now run down the acid from burette drop wise carefully till the
color of the solution changes form pink to colorless pemanentlyand stop running
down acid from burette immediately and note down the reading of burette i.e., the
volume of acid consumed in phenolphthalein . Let this volume be Vp.
5. Now add few drops (1-2 ) of methyl orange from dropper and
observe color of the solution again .If you find it yellow then titrate it with the
acid similarly as above till the color of the solution changes from yellow to orange
permanently and stop running down acid further immediately .Now note down the
reading burette from initial value i.e., the volume of acid consumed in methyl
orange .Let it be as Vm.
6. Now correlate the relation of Vp and Vm as given in table below
and find out the nature of alkalinity and then calculate the extent the alkalinity by
applying formula of law of equivalence. Repeat this experiment at lest three times
to have more accurate value
Table-1
Sr.No. Result of
Titrtion
Hydroxide ion
(OH-)
1 Vp = 0
Nil
2 Vp =Vm
Vp or Vm
3 Vp =1/2 Vm Nil
4 Vp 1/2 Vm (2Vp - Vm )
Alkalinity due to
Carbonate ion
(CO3- 2 )
Nil
Nil
2Vp
2(Vm - Vp )
Bicarbonate ion
(HCO-3)
Vm
Nil
Nil
Nill
5 Vp <1/2 Vm Nil
2Vp
Vm - 2Vp
CALCULATION
Table-2
S.No.
1
2
3
Volume (in
ml)of Water
Sample taken
Volume of HCl (in mL) run down Volume of HCl (in
for
mL) run down for
Methyl Orange(Vm)
Phenolpthaline Indicator(Vp)
20
20
20
Now apply
V1N1 = V2N2
V1= volume of alkaline water , N1 = Normality of alkaline water to be known
V2 = volume of acid consumed & N2 = normality of acid i.e,= N/50
N1 = V2N2/ V1 = N/50x V2/ V1 = ( 50000/50) x (V2/20) = 50 V2 in terms of CaCO3 equivalent
RESULT: Alkalinity of the given water sample is ………….. ppm.
JAGADGURU DATTATRAY COLLEGE OF TECHNOLOGY
ENGINEERING CHEMISTRY LAB
EXPERIMENT No – 4
Objective: Determination of alkalinity of a given water sample (2)using
N/50 HCL as a intermediate solution .
Apparatus Required: Burette, Pipette, Conical Flask, Beaker, Test Tube, Burette
Stand.
Reagent required : N/50 HCl solution , alkaline water , phenolphthalein
indicator and
methyl orange indicator etc
Some Basic Defination : Alkanility ofwater can be defined as the capacity to neutralize acid
Alkalinity of natural water may be attributed to the presence of salt of weak acid such as
bicarbonate, phosphate, silicates and water treated by lime soda process may contain
considerable quantities of carbonate & hydroxide alkalinity.
Theory : The alkalinity of water can be considered to be mainly due to the presence of the
following ions
i.
ii.
iii.
Hydroxides (OH)
Carbonates (CO32)
Bicarbonates (H CO3)
iv.
v.
Hydroxide & Carbonates (OH+ CO32)
Bicarbonates &Carbonates (H CO3+ CO3
Phenolphthalein Indicator
(works at PH range b/w 8.3 to 10.0
)
Methyl Orange Indicator (works at PH range b/w 3.1 to 4.4 )
Procedure: 1. First rinse the burette with the given solution of HCl and fill it up
to mark
2. Pipette out 20 or 25 ml of sample alkaline water in a 250ml
conical flask .
3. Add 2-3 drop of phenolphthalein by dropper in alkaline
sample water and observe colour of the solution
4. Now run down the acid from burette drop wise carefully till the
color of the solution changes form pink to colorless pemanentlyand stop running
down acid from burette immediately and note down the reading of burette i.e., the
volume of acid consumed in phenolphthalein . Let this volume be Vp.
5. Now add few drops (1-2 ) of methyl orange from dropper and
observe color of the solution again .If you find it yellow then titrate it with the
acid similarly as above till the color of the solution changes from yellow to orange
permanently and stop running down acid further immediately .Now note down the
reading burette from initial value i.e., the volume of acid consumed in methyl
orange .Let it be as Vm.
6. Now correlate the relation of Vp and Vm as given in table below
and find out the nature of alkalinity and then calculate the extent the alkalinity by
applying formula of law of equivalence. Repeat this experiment at lest three times
to have more accurate value
Table-1
Sr.No. Result of
Titrtion
Hydroxide ion
(OH-)
1 Vp = 0
Nill
2 Vp =Vm
Vp or Vm
3 Vp =1/2 Vm Nill
4 Vp 1/2 Vm (2Vp - Vm )
5 Vp <1/2 Vm Nill
Alkalinity due to
Carbonate ion
(CO3- 2 )
Nill
Nill
2Vp
2(Vm - Vp )
2Vp
Bicarbonate ion
(HCO-3)
Vm
Nill
Nill
Nill
Vm - 2Vp
CALCULATION
Table-2
S.No.
1
2
3
Volume (in
ml)of Water
Sample taken
Volume of HCl (in mL) run down Volume of HCl (in
for
mL) run down for
Methyl Orange(Vm)
Phenolpthaline Indicator(Vp)
20
20
20
Now apply
V1N1 = V2N2
V1= volume of alkaline water , N1 = Normality of alkaline water to be known
V2 = volume of acid consumed & N2 = normality of acid i.e,= N/50
N1 = V2N2/ V1 = N/50x V2/ V1 = ( 50000/50) x (V2/20) = 50 V2 in terms of CaCO3 equivalent
RESULT: Alkalinity of the given water sample is ………….. ppm
JAGADGURU DATTATRAY COLLEGE OF TECHNOLOGY
ENGINEERING CHEMISTRY LAB
EXPERIMENT – 5
Experiment No: 07
Date of conduction:
/
/ 20….
Date of submission:
/
/ 20….
Object: Estimation of Chlorides of a water sample by Argentometric
method ( Mohr’s method).
Apparatus& Chemicals Required: Burette, Burette Stand, Pipette,
Conical flask, Standard (N/50 AgNO3 )Solution, Water Sample,
Potassium Chromate Indicator.
Theory: Chlorides are present in water sample usually as NaCl, MgCl2,
and CaCl2 Although Chlorides are not harmful as such their
concentration more than 250 ppm imparts a peculiar taste to the water.
Thus the water is unacceptable for drinking and for domestic point of
viewand in boiler feed water salt like MgCl2 may under go hydrolysis
under the high presence and temperature prevailing in the boiler
generating hydrochloric acid causes corrosion in the boiler parts.
Chlorides ions can be determined by titration with standard Silver
Nitrate (AgNO3) solution using Potassium Chromate as indicator
(Mohr’s salt method). As the titration proceeds, the chlorides ion present
reacts with AgNO3 forming insoluble white precipitate of AgCl because
the solubility of AgCl is less thans that of Ag2CrO4..As soon as the
entire chloride ion is removed in the form of AgCl, the extra drop of
AgNO3 reacts with the indicator forming Red Silver Chromate. Thus,
the change of color from bright yellow to faint but distinct reddish brown
color marks the end-point.
NaCl + AgNO3  AgCl ↓ (White ppt)
2AgNO3 + K2CrO4  Ag2CrO4↓ (red ppt)
PROCEDURE: 1 First rinse the burette and fill the burette with( N/50
)AgNO3 Solutionthat you have been provided upto mark
2 . Pipette out 25 ml of given water sample containing
Cl ion in 250ml conical flask and add nearly 1ml K2CrO4 indicator in it.
-
3.
Now Slowly add( N/50 )AgNO3 Solution from burette .Initially ,White
precipitate is obtained. Continue the addition of AgNO3 Solution till
permanent reddish brown colour is obtained. As soon as you get
permanent reddish brown color stop supplying of AgNO3 Solution and
note down the reading of burette i.e., the volume of AgNO3 Solution.
Let it be V1,V2 and V3 for three consecutive readings.
28
Table: 01
S.No.
Volume of Water
Volume of N/50AgNO3sol.(in mL) run down
Sample taken
1
25ml
2
25ml
V1
V2
V3
3
25ml
Calculations : The average volume of AgNO3 Solution for three consecutive
readings= (V1+V2+V3)/3=V AgNO3. Now , apply
V1N1 = V2N2
V1= volume of water , N1 = Normality of water to be known
V2 = volume of consumed AgNO3 Solution & N2 = normality of AgNO3 Solution i.e,= N/50
25ml xN1 = N/50 x V AgNO3
OR N1= (N/50 )x (1/25ml)x V AgNO3
Strength of Cl- ions = (35.5 x1000mg /50 )x (1/25ml)x V AgNO3 = 28.4 x volume
of silver nitrate in ppm
RESULT : Amount of chloride ion present in water =---------mg/lit=---------ppm
QUESTIONS
1 . what is the importance of estimation of chloride ions
2. why AgCl is precipitated in presence of Ag2CrO4 , both are formed during reaction.
3. What do you mean by end point ?