Pick out the correct statement. (A) Chemical oxygen demand (COD) is a measure of chemically oxidisable organic matter present in water (B) COD is determined by oxidising the organic matter present in water with potassium dichromate in cone, sulphuric acid solution at boiling temperature for specified time (C) COD is related to BOD of a given waste in water but the relationship varies for different wastes. Typically COD of potable water may be 1-2 mg/litre (D) All (A), (B) and (C)

Pick out the correct statement.
(A) Chemical oxygen demand (COD) is a measure of chemically oxidisable
organic matter present in water
(B) COD is determined by oxidising the organic matter present in water with
potassium dichromate in cone, sulphuric acid solution at boiling temperature for
specified time
(C) COD is related to BOD of a given waste in water but the relationship
varies for different wastes. Typically COD of potable water may be 1-2 mg/litre
(D) All (A), (B) and (C)
by

1 Answer

Answer :

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

Related questions

Pick out the wrong statement.(A) Biological oxygen demand (BOD) is a characteristic and not a constituent of water (B) BOD is a measure of the amount of oxygen which will be demanded & used in 5 days by the biological decomposition of the organic matter present in water stream present as food for the living organism (C) BOD is expressed in mg/litre (typically, BOD=2.5 mg/litre for potable water) (D) None of these

Description : Pick out the wrong statement. (A) Biological oxygen demand (BOD) is a characteristic and not a constituent of water (B) BOD is a measure of the amount of oxygen which will be demanded & used in 5 days ... BOD is expressed in mg/litre (typically, BOD=2.5 mg/litre for potable water) (D) None of these

Last Answer : (D) None of these

To test chemical oxygen demand (C.O.D.) of sewage, organic matter is oxidised by potassium dichromate in the presence of A. Hydrochloric acid B. Sulphuric acid C. Nitric acid D. Citric acid

Description : To test chemical oxygen demand (C.O.D.) of sewage, organic matter is oxidised by potassium dichromate in the presence of A. Hydrochloric acid B. Sulphuric acid C. Nitric acid D. Citric acid

Last Answer : ANS: B

Biological Oxygen Demand (BOD) is a measure of: a. Industrial wastes poured into water bodies b. Extent to which water is polluted with organic compounds c. Amount of carbon monoxide inseparably combined with haemoglobin d. Amount of oxygen needed by green plants during night

Description : Biological Oxygen Demand (BOD) is a measure of: a. Industrial wastes poured into water bodies b. Extent to which water is polluted with organic compounds c. Amount of carbon monoxide inseparably combined with haemoglobin d. Amount of oxygen needed by green plants during night

Last Answer : Ans: A

The term Biological Oxygen Demand (BOD) is used in relation to (A) Potable water (B) Cooling water (C) Distilled water (D) Industrial effluents

Description : The term Biological Oxygen Demand (BOD) is used in relation to (A) Potable water (B) Cooling water (C) Distilled water (D) Industrial effluents

Last Answer : (D) Industrial effluents

Lagoons used for purification of polluted water (A) Are large shallow artificial lakes also known as clarification lakes, maturation ponds or oxidation ponds (B) Use micro-organisms/bacteria in presence of dissolved oxygen (C) Gives an excellent final effluent (with 3 to 4 lagoons arranged in series) having suspended solid < 1 mg/litre and BOD = 3.8 mg/litre (D) All (A), (B) & (C)

Description : Lagoons used for purification of polluted water (A) Are large shallow artificial lakes also known as clarification lakes, maturation ponds or oxidation ponds (B) Use micro-organisms/bacteria in presence of dissolved oxygen (C) Gives an ... 1 mg/litre and BOD = 3.8 mg/litre (D) All (A), (B) & (C)

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

What do you understand by the term Dark Fermentation'? (1) It is a method to dispose nu-clear wastes. (2) It is a method to produce methane from organic wastes. (3) It is a method to reduce COD in the atmosphere. (4) It is a method to produce Hydrogen as a fuel from waste water.

Description : What do you understand by the term Dark Fermentation'? (1) It is a method to dispose nu-clear wastes. (2) It is a method to produce methane from organic wastes. (3) It is a method to reduce COD in the atmosphere. (4) It is a method to produce Hydrogen as a fuel from waste water.

Last Answer : (4) It is a method to produce Hydrogen as a fuel from waste water. Explanation: Dark fermentation is the fermentative conversion of organic substrate to bio-hydrogen. It is a complex ... . Wastewater is used as a potential substrate for bio-hydrogen production in the dark fermentation process.

What do you understand by the term ‘Dark Fermentation’? (1) It is a method to dispose nuclear wastes. (2) It is a method to produce methane from organic wastes. (3) It is a method to reduce COD in the atmosphere. (4) It is a method to produce Hydrogen as a fuel from waste water.

Description : What do you understand by the term ‘Dark Fermentation’? (1) It is a method to dispose nuclear wastes. (2) It is a method to produce methane from organic wastes. (3) It is a method to reduce COD in the atmosphere. (4) It is a method to produce Hydrogen as a fuel from waste water.

Last Answer :  It is a method to produce Hydrogen as a fuel from waste water.

A 'breath test' used by traffic police to check drunken driving uses: (1) potassium dichromate-sulphuric acid (2) potassium permanganate-sulphuric acid (3) turmeric on filter paper (4) silica gel coated with silver nitrate

Description : A 'breath test' used by traffic police to check drunken driving uses: (1) potassium dichromate-sulphuric acid (2) potassium permanganate-sulphuric acid (3) turmeric on filter paper (4) silica gel coated with silver nitrate

Last Answer : (1) potassium dichromatesulphuric acid Explanation: The main constituent of alcohol is Ethanol and the concentration of ethanol in a sample can be determined by back titration with acidified potassium ... contact with the yellow dichromate-coated crystals, the color changes from yellow to green.

A ‘breath test’ used by traffic police to check drunken driving uses: (1) potassium dichromate-sulphuric acid (2) potassium perma-nganatesulphuric acid (3) turmeric on filter paper (4) silica gel coated with silver nitrate

Description : A ‘breath test’ used by traffic police to check drunken driving uses: (1) potassium dichromate-sulphuric acid (2) potassium perma-nganatesulphuric acid (3) turmeric on filter paper (4) silica gel coated with silver nitrate

Last Answer : potassium dichromate-sulphuric acid

COD of raw municipal sewage may be in the range of about __________ mg/litre. (A) 1-2 (B) 5-10 (C) 90-120 (D) 1500-2500

Description : COD of raw municipal sewage may be in the range of about __________ mg/litre. (A) 1-2 (B) 5-10 (C) 90-120 (D) 1500-2500

Last Answer : (C) 90-120

In the context of the chemical process industries, the term BOD is normally associated with the (A) Characterisation of solid wastes (B) Organic concentration in gaseous effluents (C) Characterisation of liquid effluents (D) Characterisation of boiler feed water

Description : In the context of the chemical process industries, the term BOD is normally associated with the (A) Characterisation of solid wastes (B) Organic concentration in gaseous effluents (C) Characterisation of liquid effluents (D) Characterisation of boiler feed water

Last Answer : (C) Characterisation of liquid effluents

BOD of raw municipal sewage may be in the range of about __________ mg/litre. (A) 1-2 (B) 5-10 (C) 150-300 (D) 2000-3000

Description : BOD of raw municipal sewage may be in the range of about __________ mg/litre. (A) 1-2 (B) 5-10 (C) 150-300 (D) 2000-3000

Last Answer : (C) 150-300

Measuring Biochemical Oxygen Demand (BOD) is a method used for (a) estimating the amount of organic matter in sewage water (b) working out the efficiency of oil driven automobile engines (c) measuring the activity of Saccharomyces cerevisiae in producing curd on a commercial scale (d) working out the efficiency of RBCs about their capacity to carry oxygen.

Description : Measuring Biochemical Oxygen Demand (BOD) is  a method used for  (a) estimating the amount of organic matter in  sewage water (b) working out the efficiency of oil driven  automobile engines ... commercial  scale (d) working out the efficiency of RBCs about their  capacity to carry oxygen.

Last Answer : (a) estimating the amount of organic matter in  sewage water

Measuring Biochemical Oxygen Demand (BOD) is a method used for (a) estimating the amount of organic matter in sewage water (b) working out the efficiency of oil driven automobile engines (c) measuring the activity of Saccharomyces cerevisiae in producing curd on a commercial scale (d) working out the efficiency of RBCs about their capacity to carry oxygen.

Description : Measuring Biochemical Oxygen Demand (BOD) is a method used for (a) estimating the amount of organic matter in sewage water (b) working out the efficiency of oil driven automobile engines (c) ... a commercial scale (d) working out the efficiency of RBCs about their capacity to carry oxygen.

Last Answer : (a) estimating the amount of organic matter in sewage water

72. Measuring Biochemical Oxygen Demand (BOD) is a method used for (1) Working out the efficiency of R.B.Cs. about their capacity to carry oxygen (2) Estimating the amount of organic matter is sewage water (3) Working out the efficiency of oil driven automobile engines (4) Measuring the activity of Sacccharomyces cerevisae in producing curd on a commercial scale

Description : 72. Measuring Biochemical Oxygen Demand (BOD) is a method used for (1) Working out the efficiency of R.B.Cs. about their capacity to carry oxygen (2) Estimating the amount of ... driven automobile engines (4) Measuring the activity of Sacccharomyces cerevisae in producing curd on a commercial scale

Last Answer : Estimating the amount of organic matter is sewage water

High value of BOD (Biochemical Oxygen Demand) indicates that (a) water is less polluted (b) consumption of organic matter in the water is higher by the microbes (c) water is pure (d) water is highly polluted.

Description : High value of BOD (Biochemical Oxygen Demand)  indicates that (a) water is less polluted (b) consumption of organic matter in the water is  higher by the microbes  (c) water is pure (d) water is highly polluted.

Last Answer : (b) consumption of organic matter in the water is 

High value of BOD (Biochemical Oxygen Demand) indicates that (a) water is less polluted (b) consumption of organic matter in the water is higher by the microbes (c) water is pure (d) water is highly polluted.

Description : High value of BOD (Biochemical Oxygen Demand) indicates that (a) water is less polluted (b) consumption of organic matter in the water is higher by the microbes (c) water is pure (d) water is highly polluted.

Last Answer : (b) consumption of organic matter in the water is higher by the microbes

Which is the best and the most effective method for the removal of organic contaminant present in the polluted water in very small quantity (say < 200 mg/litre)? (A) Lagooning (B) Activated carbon adsorption (C) Biological oxidation pond (D) Chemical coagulation

Description : Which is the best and the most effective method for the removal of organic contaminant present in the polluted water in very small quantity (say < 200 mg/litre)? (A) Lagooning (B) Activated carbon adsorption (C) Biological oxidation pond (D) Chemical coagulation

Last Answer : (B) Activated carbon adsorption

Biochemical Oxygen Demand (BOD) of sewage is the (a) Oxygen required to oxidise (b) Oxygen required to oxidise biologically inactive organic matter* (c) a and b both (d) none of these

Description : Biochemical Oxygen Demand (BOD) of sewage is the (a) Oxygen required to oxidise (b) Oxygen required to oxidise biologically inactive organic matter* (c) a and b both (d) none of these

Last Answer : (b) Oxygen required to oxidise biologically inactive organic matter*

Pick out the wrong statement. (A) Conversion of SO2 to SO3 in Monsanto-4 pass converter is about 98% (B) The chemical formula of oleum is H2S2O7 , which is formed by saturating sulphuric acid with sulphur trioxide (C) Vitriol oil is nothing but technical sulphuric acid (D) Decomposition of sulphuric acid on heating does not start before its boiling

Description : Pick out the wrong statement. (A) Conversion of SO2 to SO3 in Monsanto-4 pass converter is about 98% (B) The chemical formula of oleum is H2S2O7 , which is formed by saturating ... but technical sulphuric acid (D) Decomposition of sulphuric acid on heating does not start before its boiling

Last Answer : (D) Decomposition of sulphuric acid on heating does not start before its boiling

Biochemical oxygen demand (BOD) in a river water (a) has no relationship with concentration of oxygen in the water (b) gives a measure of Salmonella in the water (c) increases when sewage gets mixed with river water (d) remains unchanged when algal bloom occurs.

Description : Biochemical oxygen demand (BOD) in a river water (a) has no relationship with concentration of  oxygen in the water (b) gives a measure of Salmonella in the water (c) increases when sewage gets mixed with river  water (d) remains unchanged when algal bloom occurs.

Last Answer : (c) increases when sewage gets mixed with river  water

Consider the following statements : Activated sludge process can be said to comprise : 1. Conversion of dissolved organic matter into biological flocs 2. Removal of dissolved BOD of the waste water 3. Digestion of the sludge Which of these statements are correct ? (a) 1, 2 and 3 (b) 1 and 2 only (c) 2 and 3 only (d) 1 and 3 only

Description : Consider the following statements : Activated sludge process can be said to comprise : 1. Conversion of dissolved organic matter into biological flocs 2. Removal of dissolved BOD of the waste water 3. Digestion of the sludge Which ... 2 and 3 (b) 1 and 2 only (c) 2 and 3 only (d) 1 and 3 only

Last Answer : (b) 1 and 2 only

Asphalts are(A) Low molecular weight & low boiling point compounds present in petroleum (B) Desirable in catalytic cracking feedstock, because they produce coke (C) Readily oxidisable and form carbonaceous sludge (D) All (A), (B) & (C)

Description : Asphalts are (A) Low molecular weight & low boiling point compounds present in petroleum (B) Desirable in catalytic cracking feedstock, because they produce coke (C) Readily oxidisable and form carbonaceous sludge (D) All (A), (B) & (C)

Last Answer : (C) Readily oxidisable and form carbonaceous sludge

What happens when ethanol is heated with acidified potassium dichromate solution? Write the chemical equation.

Description : What happens when ethanol is heated with acidified potassium dichromate solution? Write the chemical equation.

Last Answer : Answer. Ethanol is oxidised to ethanoic acid with the help of acidified K2Cr2O7. CH3CH2OH + 2O → CH3COOH + H2O

Pick out the wrong statement. (A) 'Green acid' is the other name of phosphoric acid produced by the reaction of phosphate rock & sulphuric acid (B) Chemically unreactive nature of red phosphorous is due to its polymeric structure (C) Red phosphorous is the most reactive allotropic form of phosphorous (D) Red phosphorous, which is used in the manufacture of safety matches, is converted into white phosphorous by vaporisation followed by condensation

Description : Pick out the wrong statement. (A) 'Green acid' is the other name of phosphoric acid produced by the reaction of phosphate rock & sulphuric acid (B) Chemically unreactive nature of ... in the manufacture of safety matches, is converted into white phosphorous by vaporisation followed by condensation

Last Answer : (C) Red phosphorous is the most reactive allotropic form of phosphorous

Pick out the wrong statement. (A) Pulverised fuel can be completely burnt with less percentage of excess air compared to lump coal (B) Low grade coal can be used, but generally high volatile matter coals are more suitable for making pulverised fuel (C) Regulation of furnace temperature and atmosphere (oxidising or reducing) is easily possible with pulverised fuel firing (D) None of these

Description : Pick out the wrong statement. (A) Pulverised fuel can be completely burnt with less percentage of excess air compared to lump coal (B) Low grade coal can be used, but generally high volatile ... and atmosphere (oxidising or reducing) is easily possible with pulverised fuel firing (D) None of these

Last Answer : (D) None of these

(2) amount of oxygen used for biochemical oxidation Explanation: Biochemical oxygen demand or B.O.D. is the amount of dissolved oxygen needed by aerobic biological organisms in a body of water to break down organic material present in a given water sample at certain temperature over a specific time period. The term also refers to a chemical procedure for determining this amount. This is not a precise quantitative test, although it is widely used as an indication of the organic quality of water.

Description : (2) amount of oxygen used for biochemical oxidation Explanation: Biochemical oxygen demand or B.O.D. is the amount of dissolved oxygen needed by aerobic biological organisms in a body of water to ... quantitative test, although it is widely used as an indication of the organic quality of water.

Last Answer : The addition of gypsum to port-land cement helps in : (1) increasing the strength of cement (2) rapid setting of cement (3) preventing rapid setting of cement (4) reduction in the cost of cement

Phenolic water generated in coke ovens & by-product plant attached to an integrated steel plant containing phenol in concentration of less than 100 mg/litre can be removed by (A) Chlorination (B) Treating in biological oxygen pond (C) Chemical coagulation (D) None of these

Description : Phenolic water generated in coke ovens & by-product plant attached to an integrated steel plant containing phenol in concentration of less than 100 mg/litre can be removed by (A) Chlorination (B) Treating in biological oxygen pond (C) Chemical coagulation (D) None of these

Last Answer : (B) Treating in biological oxygen pond

If a 2% solution of sewage sample is incubated for 5 days at 20°C and the dissolved oxygen depletion was found to be 8 mg/l. The BOD of the sewage is A. 100 mg/l B. 200 mg/l C. 300 mg/l D. 400 mg/l

Description : If a 2% solution of sewage sample is incubated for 5 days at 20°C and the dissolved oxygen depletion was found to be 8 mg/l. The BOD of the sewage is A. 100 mg/l B. 200 mg/l C. 300 mg/l D. 400 mg/l

Last Answer : ANS: D

Biological oxygen demand (BOD) is a measure of

Description : Biological oxygen demand (BOD) is a measure of

Last Answer : Biological oxygen demand (BOD) is a measure of A. Industrial wastes poured into water bodies ... Amount of oxygen needed by green plants during night

Assertion: Amount of biodegradable organic matter present in water is measured by BOD of water Reason: During biodegradation of organic compounds. Oxy

Description : Assertion: Amount of biodegradable organic matter present in water is measured by BOD of water Reason: During biodegradation of organic compounds. Oxy

Last Answer : Assertion: Amount of biodegradable organic matter present in water is measured by BOD of water Reason: ... but reason is wrong D. both are wrong

Saw dust can be rendered chemically inert by boiling it in water containing (A) Ferrous sulphate (B) Potassium chloride (C) Ammonia (D) Nitric acid

Description : Saw dust can be rendered chemically inert by boiling it in water containing (A) Ferrous sulphate (B) Potassium chloride (C) Ammonia (D) Nitric acid

Last Answer : Answer: Option A

Thiamin is oxidized to thiochrome in alkaline solution by (A) Potassium permanganate (B) Potassium ferricyanide (C) Potassium chlorate (D) Potassium dichromate

Description : Thiamin is oxidized to thiochrome in alkaline solution by (A) Potassium permanganate (B) Potassium ferricyanide (C) Potassium chlorate (D) Potassium dichromate

Last Answer : Answer : B

A green coloured solid compound ̳X‘, gets oxidized to reddish brown solid in presence of air. ̳X‘ on heating gives brown coloured solid ̳Y‘ and two pungent smelling gases ̳A‘ and ̳B‘. ̳A‘ turns acidified potassium dichromate solution green. Name ̳X‘, ̳Y‘, ̳A‘ , ̳B‘ and type of Reaction. (a) CuSO 4 , CuO, SO 2 , SO 3 , decomposition (b) FeSO 4 , Fe, SO 2 , SO 3 , decomposition (c) FeSO 4 , Fe 2 O 3, SO 2 , SO 3 , decomposition (d) FeSO 4 , Fe 2 O 3 , SO 3 , SO 2 , decomposition

Description : A green coloured solid compound ̳X , gets oxidized to reddish brown solid in presence of air. ̳X on heating gives brown coloured solid ̳Y and two pungent smelling gases ̳A and ̳B . ̳A turns acidified potassium ... , SO 3 , decomposition (d) FeSO 4 , Fe 2 O 3 , SO 3 , SO 2 , decomposition

Last Answer : (c) FeSO 4 , Fe 2 O 3, SO 2 , SO 3 , decomposition

The presence of free ammonia in sewage, is detected by A. Boiling B. Adding potassium permanganate C. Adding sulphuric acid D. Phenol-di-sulphuric acid

Description : The presence of free ammonia in sewage, is detected by A. Boiling B. Adding potassium permanganate C. Adding sulphuric acid D. Phenol-di-sulphuric acid

Last Answer : ANS: A

What are the chemical signals of Potassium Dichromate ?

Last Answer : : Chemical signal of potassium dichromate K2Cr2O7

Thermal pollution of water increases its toxicity and oxidation of oxygen demanding waste besides favouring bacterial growth. A rise in water temperature by 10°C, doubles the toxic effects of __________ present in it. (A) Coal ash (B) Potassium cyanide (C) Ortho-xylene (D) None of these

Description : Thermal pollution of water increases its toxicity and oxidation of oxygen demanding waste besides favouring bacterial growth. A rise in water temperature by 10°C, doubles the toxic effects of __________ present in it. (A) Coal ash (B) Potassium cyanide (C) Ortho-xylene (D) None of these

Last Answer : (B) Potassium cyanide

Pick out the wrong statement. (A) Biological oxygen demand (B.O.D.) value of a sewerage sample is always lower than its chemical oxygen demand (C.O.D.) value (B) Environmental pollution by NOx emission is much higher by four stroke petrol engines as compared to the two stroke engines (C) Temperature in stratosphere rises with increasing altitude (D) The characteristic of a green house body is that it allows the long wavelength incoming solar radiation to come in but does not allow the short wavelength infra red radiation to escape out of the earth's atmosphere

Description : Pick out the wrong statement. (A) Biological oxygen demand (B.O.D.) value of a sewerage sample is always lower than its chemical oxygen demand (C.O.D.) value (B) Environmental pollution by ... in but does not allow the short wavelength infra red radiation to escape out of the earth's atmosphere

Last Answer : (D) The characteristic of a green house body is that it allows the long wavelength incoming solar radiation to come in but does not allow the short wavelength infra red radiation to escape out of the earth's atmosphere

Bio-chemical oxygen demand (BOD) for the first 20 days in generally referred to A. Initial demand B. First stage demand C. Carbonaceous demand D. All of these

Description : Bio-chemical oxygen demand (BOD) for the first 20 days in generally referred to A. Initial demand B. First stage demand C. Carbonaceous demand D. All of these

Last Answer : ANS: D

Biochemical Oxygen Demand (BOD) may not be a good index for pollution for water bodies receving effluents from:

Description : Biochemical Oxygen Demand (BOD) may not be a good index for pollution for water bodies receving effluents from:

Last Answer : Biochemical Oxygen Demand (BOD) may not be a good index for pollution for water bodies receving ... sewage C. Dairy industry D. Petroleum industry

Biochemical Oxygen Demand (BOD) may not be a good index for pollution for water bodies receiving effluents from (a) domestic sewage (b) dairy industry (c) petroleum industry (d) sugar industry.

Description : Biochemical Oxygen Demand (BOD) may not be a  good index for pollution for water bodies receiving  effluents from (a) domestic sewage (b) dairy industry (c) petroleum industry (d) sugar industry.

Last Answer : c) petroleum industry

Biochemical Oxygen Demand (BOD) may not be a good index for pollution for water bodies receiving effluents from (a) domestic sewage (b) dairy industry (c) petroleum industry (d) sugar industry.

Description : Biochemical Oxygen Demand (BOD) may not be a good index for pollution for water bodies receiving effluents from (a) domestic sewage (b) dairy industry (c) petroleum industry (d) sugar industry.

Last Answer : (c) petroleum industry

The mass of a body is different from its weight because 1. mass is a variable quantity whereas weight is constant 2. mass varies very little at different places whereas weight varies a lot 3. mass is constant but weight decreases as the body moves from the poles to the equator 4. mass is a measure of the quantity of matter whereas weight is a force Which of the above statements is/are correct? (a) 1 only (b) 2 and 4 (c) 3 only (d) 3 and 4

Description : The mass of a body is different from its weight because 1. mass is a variable quantity whereas weight is constant 2. mass varies very little at different places whereas weight varies a lot 3. mass is constant but weight decreases as ... is/are correct? (a) 1 only (b) 2 and 4 (c) 3 only (d) 3 and 4

Last Answer : Ans:(d)

Pick out the correct statement. (A) In catalytic reactions, the catalyst reacts with the reactants (B) A catalyst initiates a chemical reaction (C) A catalyst lowers the activation energy of the reacting molecules (D) A catalyst cannot be recovered chemically unchanged at the end of the chemical reaction

Description : Pick out the correct statement. (A) In catalytic reactions, the catalyst reacts with the reactants (B) A catalyst initiates a chemical reaction (C) A catalyst lowers the activation energy of ... molecules (D) A catalyst cannot be recovered chemically unchanged at the end of the chemical reaction

Last Answer : (C) A catalyst lowers the activation energy of the reacting molecules

concentrated sulphuric acid on reaction with NaCl, NaBr and Nal produces HCl, bromine and iodine respectively. What order of oxidising ability of halo

Description : concentrated sulphuric acid on reaction with NaCl, NaBr and Nal produces HCl, bromine and iodine respectively. What order of oxidising ability of halo

Last Answer : concentrated sulphuric acid on reaction with NaCl, NaBr and Nal produces HCl, bromine and iodine respectively. What ... gt l_(2) gt H_(2)SO_(4)`

For the COD test of sewage, organic matter is oxidised by K2Cr2O7 in the presence of A. H2SO4 B. HNO3 C. HCl D. None of these

Description : For the COD test of sewage, organic matter is oxidised by K2Cr2O7 in the presence of A. H2SO4 B. HNO3 C. HCl D. None of these

Last Answer : ANS: A

Pick up the correct statement from the following: (A) Phase of a wave is expressed as a fraction of a period with respect to a reference (B) Phase is usually specified by angular measure with one period being 360° (C) The reference for finding the phase of a wave is taken from the previous passage through zero from the negative to the positive direction (D) All of these

Description : Pick up the correct statement from the following: (A) Phase of a wave is expressed as a fraction of a period with respect to a reference (B) Phase is usually specified by angular measure with ... from the previous passage through zero from the negative to the positive direction (D) All of these

Last Answer : Answer: Option D

The ratio of oxygen available to the oxygen required for stabilisation of sewage is called the (A) Bacterial stability factor (B) Relative stability (C) Biological oxygen demand (BOD) (D) Oxygen ion concentration

Description : The ratio of oxygen available to the oxygen required for stabilisation of sewage is called the (A) Bacterial stability factor (B) Relative stability (C) Biological oxygen demand (BOD) (D) Oxygen ion concentration

Last Answer : (B) Relative stability

Use of chlorine in the treatment of sewage (A) Helps in grease separation (B) Increases the biological oxygen demand (BOD) (C) Causes bulking of activated sludge (D) Aids in flocculation

Description : Use of chlorine in the treatment of sewage (A) Helps in grease separation (B) Increases the biological oxygen demand (BOD) (C) Causes bulking of activated sludge (D) Aids in flocculation

Last Answer : (A) Helps in grease separation

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

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