21CH12 Cie 1
21CH12 Cie 1
21CH12 Cie 1
2 a Explain the redox titration principle and procedure used for the estimation of 6 2 1
chemically oxidisable waste in industrial waste water.
Redox titration Principle:…… 1M
Blank titration : ……. 2M
Back titration: ….. . 2 M
Role of Ag2SO4 & HgSO4: … 1M
b Calculate the temporary and permanent hardness of water sample having the 4 3 3
following constituents per litre: Ca(HCO3)2 = 162 mg, MgCl2 = 95 mg , NaCl = 585
mg/dm3, Mg(HCO3)2 = 73 mg/dm3, CaSO4 =36 mg/dm3
(amu of Ca = 40, Mg = 24, Cl=35.5, C=12, S=32, O=16).
3 a Outline the process involved in the primary and secondary treatments of sewage 6 1 3
water with suitable diagram.
4 a In a petrol engine, the shock waves created due to knocking leads to the 6 2 4
characteristic metallic sound. Explain any two possible reasons which lead to
knocking and suggest eco-friendly preventive measure?
Two reasons : 5 marks (2.5 X 2)
MTBE/any relevant answer: 1M
α-Methyl-Naphthalene Iso-octane
Cetane -100, α-Methyl-Naphthalene 0 (2 M)
Isooctane -100, n-heptane 0 (2M)
5 a Write the structure of polysulphone. Identify the hydrophilic and hydrophobic ends 6 2 2
of the membrane. How will you prepare polysulphone membrane by NIPS method?
Structure : 1M
Identification of ends: 1 M
NIPS:4M
b Evaluate the COD of waste water from the redox titration values obtained. 25 cm3 of 4 3 3
waste water was mixed with 25 cm3 of K2Cr2O7, acidified and refluxed. The
unreacted acidified K2Cr2O7 required 8.5 cm3 0.25 N FAS. In a blank titration
25 cm3 of acidified K2Cr2O7 required 16.5 cm3 of same FAS.
Ans: 640 mg/dm3
BT-Blooms Taxonomy, CO-Course Outcomes, M-Marks
Particulars CO1 CO2 CO3 CO4 L1 L2 L3 L4 L5 L6
Marks
Distribution Test Max 6 10 24 10 6 24 16 4 - -
Marks