Use of hydrated lime in water treatment
(A) Before filtration, reduces the bacterial load on filters
(B) After filtration, combats the corrosiveness of water due to the presence
of O2 & CO2
(C) Is to adjust the pH value
(D) All (A), (B) and (C)

1 Answer

Answer :

(D) All (A), (B) and (C)

Related questions

Description : Corrosiveness of steam condensate is due to the presence of (A) CO2 (B) Dissolved O2 (C) Both (A) & (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) & (B)

Description : Pick out the true statement pertaining to water treatment. (A) Slow sand filters can remove colour completely (B) Activated carbon can be used for taste & odour control without subsequent filtration ... of water (D) Normally, the turbidity is removed by adding a coagulant prior to sedimentation

Last Answer : (D) Normally, the turbidity is removed by adding a coagulant prior to sedimentation

Description : Lime and soda ash are added to water to remove (A) Bicarbonates & sulphates of calcium and magnesium (B) Undesirable taste and odour (C) Bacteria (D) Its corrosiveness

Last Answer : (A) Bicarbonates & sulphates of calcium and magnesium

Description : One of the steps during refining of cane sugar consists of addition ofhydrated lime to the sugar syrup followed by carbonation of the resulting solution. The purpose of this step is to (A) Adjust ... (C) Reduce the viscosity of the syrup (D) Improve the rate of crystallisation of sugar

Last Answer : (A) Adjust the pH of the syrup

Description : Pick up the incorrect statement from the following: (A) Iron salts produce heavy flocks and hence remove more suspended matter (B) Iron salts remove hydrogen sulphides (C) Iron salts can be used over a limited range of pH values (D) Iron salts impart corrosiveness to water

Last Answer : (C) Iron salts can be used over a limited range of pH values

Description : Pick out the false statement pertaining to water treatment. (A) Aeration of water is effective in CO2 removal (B) The zeolite water softening process reduces the hardness of water by not more than 50% (C ... carbonate do not cause hardness in water (D) Water with pH value less than 7, is acidic

Last Answer : (B) The zeolite water softening process reduces the hardness of water by not more than 50%

Description : The oxygen d issoc iat ion curve for hemoglobin is shifted to the right by (A) Decreased O2 tension (B) Decreased CO2 tension (C) Increased CO2 tension (D) Increased pH

Last Answer : Answer : C

Description : Deaeration of water in its treatment is necessary, as it (A) Minimises its turbidity (B) Helps in controlling its taste and odour (C) Minimises its corrosiveness (D) None of these

Last Answer : (C) Minimises its corrosiveness

Description : Bacterial aerobic oxidation of polluted water in biological oxidation ponds is done to purify it. Presence of bacteria helps in (A) Coagulation and flocculation of colloids (B) Oxidation of carbonaceous matter to CO2 (C) ... to the nitrite and eventually to the nitrate (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : Tubercular bacilli grow best in a. Absence of O2 b. Presence of CO2 c. Presence of O2 d. None of these

Last Answer : Ans: B

Description : Photo chemical smog is a result-ant of the reaction among – (1) High concentration of NO2, O3, and CO in the evening (2) CO, CO2 and NO2 at low temperature (3) CO, O2 and peroxy acetyl nitrate in the presence of Sunlight (4) NO2, O3 and peroxy acetyl nitrate in the presence of Sunlight

Last Answer : (4) NO2, O3 and peroxy acetyl nitrate in the presence of Sunlight Explanation: Photochemical smog is a unique type of air pollution which is caused by reactions between sunlight and pollutants like hydrocarbons and nitrogen dioxide (NO and NO2).

Description : Pick out the one which is not a chemical coagulant. (A) Aluminium sulphate (B) Ferrous sulphate (C) Hydrated lime (D) Chloramine

Last Answer : (D) Chloramine

Description : Suspended solid present in the waste water generated in blast furnace gas cooling and cleaning plant is removed by (A) Biological oxygen pond (B) Radial settling tank (thickener) using coagulant (lime & ferrous sulphate) (C) Lagoons (D) Filtration

Last Answer : (B) Radial settling tank (thickener) using coagulant (lime & ferrous sulphate)

Description : Iron & manganese present as pollutant in water cannot be removed by (A) Ion exchange process (B) Oxidation followed by settling & filtration (C) Lime soda process or manganese zeolite process (D) Chlorination

Last Answer : (D) Chlorination

Description : Impurities present in brine is normally removed by treatment with (A) NH3 and CO2 (B) Lime and soda ash (C) Lime, ammonia and carbon (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Description : Which of the following parameters of the fluid is not very important, while deciding its route in a shell and tube heat exchanger? (A) Corrosiveness & fouling characteristics (B) Pressure (C) Viscosity (D) Density

Last Answer : (D) Density

Description : Main constituents of purified Lurgi gas are (A) H2 , CmHn & CO2 (B) CO, H2 & CH4 (C) CO2 , O2 & CO (D) N2 , H2 & CO2

Last Answer : (B) CO, H2 & CH4

Description : L.D. converter gas (produced in steel plant) comprises mainly of (A) CO (upto 65%) & CO2 (B) CO2 & H2 (C) CO & O2 (D) CO2 & O2

Last Answer : (A) CO (upto 65%) & CO2

Description : Workability improved by adding (A) Fly ash (B) Hydrated lime (C) Calcium chloride (D) All the above

Last Answer : Answer: Option D

Description : The fire clay contains pure (A) Lime (B) Oxide of iron (C) Hydrated aluminium silicate (D) Magnesium

Last Answer : Answer: Option C

Description : Cement paints usually (A) Contain hydrated lime (B) Contain 5% to 10% colour pigments (C) Contain 5% sodium chloride (D) All the above

Last Answer : Answer: Option D

Description : The workability of concrete can be improved by adding (a) Hydrated lime (b) Fly ash (c) Calcium chloride (d) All the above

Last Answer : (d) All the above

Description : Consider the reaction, C + O2 ⇌ CO2; ΔH = - 94 kcal. What will be the value of ΔH for the reaction CO2 → C + O2? (A) -94 kcal (B) +94 kcal (C) > 94 kcal (D) < -94 kcal

Last Answer : (B) +94 kcal

Description : During conversion of ammonium carbamate into urea, presence of large excess of water (A) Increases the yield of urea (B) Adversely affects the yield of urea (C) Reduces the evaporator load by diluting the urea solution (D) Does not affect the yield of urea

Last Answer : (B) Adversely affects the yield of urea

Description : Pick up the correct statement from the following:  (A) Due to boiling, the bacterias present in water can be destroyed  (B) Lime may be used for softening hard water  (C) Excess lime when added to water, raises the pH value of water  (D) All the above 

Last Answer : (D) All the above 

Description : The balance of CO2 and O2 in atmosphere is due to _____. (1) Transportation (2) Photosynthesis (3) Respiration (4) Evaporation

Last Answer : (2) Photosynthesis Explanation: Photosynthesis takes in the carbon dioxide produced by all breathing organisms and reintroduces oxygen into the atmosphere.

Description : Yawning occurs– (1) due to excess concentration of CO2 in blood (2) due to excess concentration of CO2 in lungs (3) due to excess concentration of O2 in lungs (4) None of these

Last Answer : due to excess concentration of CO2 in blood

Description : Air filtration in a furnace (A) Reduces its thermal efficiency (B) Is indicated by flame sting out (C) Increases the flue gas temperature (D) None of these

Last Answer : (A) Reduces its thermal efficiency

Description : Temporary hardness of water can be removed by (A) Addition of alum (a coagulant) (B) Boiling (C) Filtration (through gravity sand filter) (D) Addition of lime

Last Answer : (B) Boiling

Description : High magnesia lime is added to hot sugar cane juice (during the manufacture of sugar) to (A) Flocculate the impurities (B) Facilitate fast filtration (C) Both (A) and (B) (D) Neither (A) nor (B)

Last Answer : (C) Both (A) and (B)

Description : Which characteristic of a fluid is not important in deciding its route in a shell and tube heat exchanger? (A) Corrosiveness (B) Fouling characteristic (C) Viscosity (D) None of these

Last Answer : (D) None of these

Description : In Orsat's apparatus, ammoniacal cuprous chloride is used for selectivity absorbing (A) CO (B) CO2 (C) O2 (D) H2O

Last Answer : (A) CO

Description : The combustion reaction, C + O2 = CO2 , is (A) Exothermic (B) Endothermic (C) Autocatalytic

Last Answer : (A) Exothermic

Description : Incomplete combustion of fuel in the furnace is judged by high __________ of the flue gases. (A) CO content (B) Dew point (C) CO2 content (D) O2 content

Last Answer : (A) CO content

Description : The sequence of absorption in flue gas analysis by Orsat's apparatus is respectively (A) CO2 , O2 , CO (B) CO, O2 , CO2 (C) CO2 , CO, O2

Last Answer : (A) CO2 , O2 , CO

Description : When incomplete combustion loss is high, the flue gas analysis shows large amount of (A) CO2 (B) CO (C) O2 (D) C

Last Answer : (B) CO

Description : Efficiency of the combustion of a fuel is judged by the __________ the flue gas. (A) % of CO2 in (B) % of O2 in (C) Temperature of (D) Colour of

Last Answer : (B) % of O2 in

Description : If CO2 is not fully absorbed by the KOH solution meant for its absorption in the orsat apparatus, it will appear as (A) O2 (B) CO (C) N2 (D) SO2

Last Answer : (D) SO2

Description : A sample of natural gas containing 80% methane (CH4 ) and rest nitrogen (N2 ) is burnt with 20% excess air. With 80% of the combustibles producing CO2 and the remainder going to CO, the Orsat analysis in volume percent is (A) CO2 : 6 ... 96, N2 :72.06 (D) CO2 : 7.60, CO : 1.90, O2 : 4.75, N2 : 85.74

Last Answer : (B) CO2 : 7.42, CO : 1.86, O2 : 4.64, N2 :86.02

Description : The pyrogallol solution used in Orsat apparatus can absorb (A) Only O2 (B) Both O2 and CO2 (C) Both O2 and CO (D) All CO, CO2 , and O2

Last Answer : (B) Both O2 and CO2

Description : The cuprous chloride used in orsat apparatus can absorb (A) Only CO (B) Both CO and CO2 (C) Both CO and O2 (D) All CO, CO2 , and O2

Last Answer : (D) All CO, CO2 , and O2

Description : The average molecular weight of a flue gas having the composition by volume as CO2 = 25%, O2 = 25%, N2 = 50% will be (A) 27.6 (B) 23 (C) 47.3 (D) 42.9

Last Answer : (B) 23

Description : The essential ingredient of all the synthesis gas is (A) H2 (B) O2 (C) CO2 (D) N2

Last Answer : (A) H

Description : The combustion reaction, C + O2 = CO2 , is (A) Exothermic (B) Endothermic (C) Autocatalytic (D) None of these

Last Answer : (A) Exothermic

Description : In the reaction, C + O2 → CO2; ΔH = - 94 kcal. What is the heat content (enthalpy) of O2? (A) -94 kcal (B) > -94 kcal (C) < - 94 kcal (D) Zero

Last Answer : (D) Zero

Description : Volumetric composition of flue gas analysed with the Orsat apparatus is : CO2 = 12%, O2 = 8%, CO = nil, N2 = 80%. This flue gas composition indicates that (A) Pure oxygen has been used for combustion ... very high (C) Excess air has been used for combustion (D) Hydrogen is not present in the fuel

Last Answer : (C) Excess air has been used for combustion

Description : During treatment of water, sedimentation is done  (A) Before filtration  (B) After filtration  (C) Simultaneously with filtration  (D) Along with chlorination 

Last Answer : (A) Before filtration 

Description : After re leas ing O2 at the tissues, hemoglobin transports (A) CO2 and protons to the lungs (B) O2 to the lungs (C) CO2 and protons to the tissue (D) Nutrients

Last Answer : Answer : A

Description : Presence of phosphorous in metallurgical coal (A) Is not undesirable (B) Reduces its calorific value (C) Badly affects the quality of steel

Last Answer : (C) Badly affects the quality of steel