BE Computer Engineering छमाही १ (इंजीनियरिंग) - University of Mumbai Important Questions

The hardness of 85000 litres of water sample was removed by passing it through a zeolite softener. The zeolite required 2000 litres of NaCl solution containing 190 mg/lit of NaCl for regeneration. calculate the hardness of sample.

What are the advantages of ion exchange process?

A 1Oml of sample of water was refluxed with 20ml potassium dichromate solution and after refluxing the excess unreacted dichromate required 26.2ml of 0. 1M FAS solution. A blank 1Oml of distilled water on refluxing with 20ml of dichromate solution required 36ml of 0. 1M FAS solution. Calculate the COD of waste water . 

Calculate the amount of lime (85% pure) and soda (95% pure) required to soften one million litre of water which contains CaCO₃ = 12. 5ppml MgCO₃ = 8.4ppml
CaCl₂ = 22.2ppml ,  MgCl₂ = 9.5ppml C0₂ = 33ppml HCI = Z3ppml  organic matter= 16.Bppm 

What are cation and anion exchangers?

A 10ml of sample of waste water was refluxed with 20ml of potassium dichromate solution and after refluxing the excess unreacted dichromate required 36.2ml of 0. 1M FAS solution. A blank of 1Om/ of distilled water on refluxing with 20ml of dichromate solution required 46ml of 0. 1M FAS solution. Calculate the COD value of waste water.

Explain the zeolite method for softening of water giving suitable diagram and reactions. What are the limitations of this method. 

Calculate the amount of lime {80 %purity) and soda {90% purity) required for softening of 50,000 of hard water whose chemical analysis results are given below. Ca(HCO₃ ) = 40.5 mg/L, Mg( HCO₃)₂ = 73.0 mg/L, MgSO₄ = 60.0 mg/L, CaSO₄ = 34.0 mg/L, CaCl₂ = 27.5 mg/L and NaCI = 20.0 mg/L.

Ten thousand litres of hard water was made soft with zeolite. The exhausted zeolite required a total amount of 8 lit of NaCl solution containing 150 gm per litre for regeneration. Calculate the hardness of water.

Explain lon-exchange process for Softening of hard water. What are its advantages and disadvantages.

Write a note on Deccay of Concrete.

15000 litres of hard water was passed through a zeolite softener. The exhausted zeolite required 120 litres of NaCI having stream of 30g/l of NaCL Calculate the hardness of water.

Write a note on Ultrafiltration method for purification of water.

Distinguish between temporary and permanent hardness of water.

Explain the principle of EDTA method .

A sample of water contains following impurities :
Mg(HCO3)2 =73 mg/lit , MgSO4 = 120 mg/lit , CaCl2 = 222 mg/lit and Ca(NO3)2 = 164 mg/lit . The purity of lime is 74% and soda is 90% . Calculate the quantity of lime and soda needed for softening of 50,000 litres of water .

A zeolite softener was completely exhausted and was generated by passing 1000 litres of NaCl .How many litres of a sample of hardness 500 ppm can be softened by this softener ?

Draw the diagram for demineralization process and write suitable reactions involved in the process .What are the advantages and disadvantages of the method .

Write a short note on Reverse Osmosis .

What is meant by Fabrication of plastics? Explain injection moulding with the help of neat diagram .