Related Questions

The correct relation between theoretical oxygen demand (TOD), Biochemical oxygen demand (BOD) and Chemical oxygen demand (COD) is given by
A TOD > BOD > COD
B TOD > COD > BOD
C BOD > COD > TOD
D COD > BOD > TOD
Gasification of the solid fuel converts its organic part into combustible by interaction with air/oxygen and steam so as to obtain a secondary gaseous fuel of high calorific value having no ash. Gasification reactions are normally carried out at about __________ °C.
A 400-500
B 900-1000
C 1400-1500
D 1700-1800
Reaction of an alcohol with organic acid is called the __________ reaction.
A Saponification
B Esterification
C Neutralisation
D Acidification
One molecule of oxygen consists of __________ atoms of oxygen.
A 2
B 4
C 8
D 16
Oxygen is separated by distillation from air after its liquefaction. The boiling point of oxygen is about __________ °C.
A -83
B -183
C -196
D -218
They are organic compounds consisting of carbon, hydrogen and oxygen present in all living organisms.
A Proteins
B Carbohydrates
C Fats
D Minerals
How the biological oxygen demand gets affected with the increased presence of organic matter in water?
A the oxygen demand increases
B the oxygen demand decreases
C the oxygen demand remains unchanged
D none of the mentioned
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
একটি অক্সিজেন সিলিন্ডারের আয়তন 10 x 105 cm3 এবং এতে 300 বায়ুমন্ডলীয় চাপে অক্সিজেন ভর্তি আছে। কিছুটা ব্যবহারের পর দেখা গেল যে, চাপ 200 বায়ুমন্ডলীয় চাপে নেমে গেছে। ব্যবহারকৃত অক্সিজেনের আয়তন কত?(The volume of an oxygen cylinder is 10 x 105 cm3 and pressure is 300 atm. After some use, the pressure drops to 200 atm. What is the volume of the used oxygen?)
A 1000 L
B 500 L
C 2000 L
D 1200 L
E 1500 L
The relative stability of a sewage sample, whose dissolved oxygen is same as the total oxygen required to satisfy BOD, is
A 1
B 100
C Infinite
D Zero

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