IRJET- Hardness Removal of Groundwater by using Optimum Lime-Soda Process
Cheasgn
1. K L University
Department of Chemistry
Semester-II, A.Y.2012-13
Assignment Test Course: Engineering Chemistry Code: 11-BS104
Max. Marks: 05 Date: 30.01.13 Time: 45 minutes
1. (a). What are the constituents that cause hardness in water? Explain the terms
‘Carbonate Hardness’ and ‘Non- Carbonate Hardness’, and indicate how these are
related to Temporary Hardness and Permanent Hardness.
[Chemistry in Engineering and Technology Vol. 2 by J C Kuriacose, J Rajaram,
Chapter 13, Q. No. 13.6, Page No. 337.]
(b). A sample of water contains the following concentrations of the ions (all in
equivalent amounts of CaCO3); Ca2+ (100ppm), Mg2+ (95ppm), Na+ (15ppm),
HCO3- (160 ppm), SO42- (40 ppm) and Cl- (10 ppm). Express the results in terms
of salts by using the guidelines given in the text.
[Chemistry in Engineering and Technology Vol. 2 by J C Kuriacose, J Rajaram,
Chapter 13, Q. No. 13.8, Page No. 337.]
(c). Explain the terms (i) Priming (ii) Foaming and (iii) Blow down
[Chemistry in Engineering and Technology Vol. 2 by J C Kuriacose, J Rajaram,
Chapter 13, Q. No. 13.15, Page No. 338.]
(d). What are the factors that lead to caustic embrittlement in boilers? How can this be
prevented?
[Chemistry in Engineering and Technology Vol. 2 by J C Kuriacose, J Rajaram,
Chapter 13, Q. No. 13.16, Page No. 338.]
2. (a). Calgon treatment prevents scale formation in boilers, Explain.
[A Text Book of Engg. Chemistry by Shashi Chawla, Chapter 6, Q.No. 1(i),
Page No. AC. 311.]
(b). Why is calgon conditioning better than phosphate conditioning?
[A Text Book of Engg. Chemistry by Shashi Chawla, Chapter 6, Q.No. 6(c),
Page No. AC. 312.]
(c). Explain (in brief) boiler corrosion.
[A Text Book of Engg. Chemistry by Shashi Chawla, Chapter 6, Q.No. 1(ii),
Page No. AC. 311.]
(d) What do you mean by Priming and Foaming? How does it take place in boilers?
[A Text Book of Engg. Chemistry by Shashi Chawla, Chapter 6, Q.No. 7(a),
Page No. AC. 312.]
(e). What is the principle of EDTA titrations? How can the permanent hardness of
water be determined by this method?
[A Text Book of Engg. Chemistry by Shashi Chawla, Chapter 6, Q.No. 2(a),
Page No. AC. 311.]
(f). Why is NH3 – NH4Cl buffer solution is added in determination of hardness of
water by EDTA titration.
[A Text Book of Engg. Chemistry by Shashi Chawla, Chapter 6, Q.No. 2(b),
Page No. AC. 311.]
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2. (g). 50 ml of a sample water consumed 15 ml of 0.01 M EDTA before boiling and 5 ml
of the same EDTA after boiling. Calculate the degree of total hardness, permanent
hardness and temporary hardness.
[A Text Book of Engg. Chemistry by Shashi Chawla, Chapter 6, Q.No. 9, Page No. AC.
317.]
3. (a). What are complexometric titrations?
[A Text Book of Engg. Chemistry by Shashi Chawla, Chapter 6, Q.No. 9(a), Page No.
AC. 312.]
(b). Explain the principle of EDTA titrations.
[A Text Book of Engg. Chemistry by Shashi Chawla, Chapter 6, Q.No. 9(b),
Page No. AC. 312.]
(c). Is it necessary to maintain the pH of the solution nearly constant by adding a
suitable buffer during EDTA titrations?
[A Text Book of Engg. Chemistry by Shashi Chawla, Chapter 6, Q.No. 9(c),
Page No. AC. 313.]
(d). Describe the process of estimation of Ca and Mg with EDTA.
[A Text Book of Engg. Chemistry by Shashi Chawla, Chapter 6, Q.No. 9(d),
Page No. AC. 313.]
(e). Draw the structure of EDTA.
[A Text Book of Engg. Chemistry by Shashi Chawla, Chapter 6, Q.No. 23(a),
Page No. AC. 318.]
(f). 0.28 gm. Of CaCO3 was dissolved in HCl and the solution was made to one litre
with distilled water. 100 ml of the above solution required 28 ml of EDTA
solution on titration. 100 ml of the hard water sample required 33 ml of the same
EDTA solution on titration. After boiling 100 ml of this water, cooling and
filtering and then titration required 10 ml of EDTA solution. Calculate the
Carbonate, Non- carbonate hardness of given sample of water in terms of ppm.
[A Text Book of Engg. Chemistry by Shashi Chawla, Chapter 6, Q.No. 7(c),
Page No. AC. 312.]
4. (a). How do you analyse alkalinity of water sample?
[Engineering Chemistry by O G Palanna, Page No. 309, Q.No.18].
(b). 100 ml of a raw water sample on titration with N/50 sulphuric acid required 12.4
ml acid to phenolphthalein end point and 15.2mlto methyl orange end point.
Determine the type and extent of alkalinity present in the water.
[Engineering Chemistry by O G Palanna, Page No. 307, Q.No.1].
(c). Mention the methods adopted for the purification o f Municipal water?
[Engineering Chemistry by O G Palanna, Page No. 309, Q.No.40].
5. (a). Distinguish between hard water and soft water.
[Engg. Chemistry 15th Edition by Jain and Jain, Chapter 1, Q.No. 3(a), Page No. 53.]
(b).What is hardness of water? Mention various units used for its expression and show
their relation also.
[Engg. Chemistry 15th Edition by Jain and Jain, Chapter 1, Q.No. 15(a), Page No. 54.]
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3. (c). Define Carbonate and non- carbonate hardness of water. List the various
disadvantages of hard water for domestic use.
[Engg. Chemistry 15th Edition by Jain and Jain, Chapter 1, Q.No. 1(a), Page No. 53.]
(d). What are the specifications of potable water?
[Engg. Chemistry 15th Edition by Jain and Jain, Chapter 1, Q.No. 10(b), Page No. 54.]
(e). A sample of water on analysis has been found to contain following in ppm.
Ca(HCO3)2 = 4.86, Mg(HCO3)2 = 5.84, CaSO4 = 6.80, MgSO4 = 8.40
Calculate the temporary and permanent hardness of the water.
(At. Wts: Ca = 40, Mg = 24, C = 12, S = 32, O = 16, H = 1)
[Engg. Chemistry 15th Edition by Jain and Jain, Chapter 1, Q.No.5, Page No. 48.]
(f). What happens when temporary hard water is boiled? Give equations.
[Engg. Chemistry 15th Edition by Jain and Jain, Chapter 1, Q.No. 14(b), Page No. 54.]
(g). Give details of scale and sludge formation in boilers and write about the methods
used for their prevention.
[Engg. Chemistry 15th Edition by Jain and Jain, Chapter 1, Q.No. 15(d),
Page No. 54.]
6. (a). What is the principle of EDTA method? Describe the estimation of hardness of
water by EDTA method.
[Engg. Chemistry 15th Edition by Jain and Jain, Chapter 1, Q.No. 3(b), Page No. 53.]
(b). 20 ml of standard hard water (containing 15 grams of CaCO3 per litre) required 25
ml EDTA solution for end- point. 100 ml of water sample required 18 ml EDTA
solution; while same water after boiling required 12 ml of EDTA solution.
Calculate Carbonate and Non- carbonate hardness of water. Which buffer is used
in this titration and what is its pH?
[Engg. Chemistry 15th Edition by Jain and Jain, Chapter 1, Q.No. 11, Page No. 48.]
(c). Explain scale formation and sludge formation in boilers. How are they removed?
[Engg. Chemistry 15th Edition by Jain and Jain, Chapter 1, Q.No. 6(a), Page No. 54.]
(d). Describe the carbonate and phosphate conditioning of water to overcome the boiler
feed problem.
[Engg. Chemistry 15th Edition by Jain and Jain, Chapter 1, Q.No. 2(a), Page No. 53.]
(e). Explain the function of calgon in water treatment.
[Engg. Chemistry 15th Edition by Jain and Jain, Chapter 1, Q.No. 7(b), Page No. 54.]
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