Answered 0 of 25 on this page · Correct 0 · Wrong 0
Q26. The pH value of pure water is—
- A2
- B7
- C9
- D14
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Answer: B) 7
Q27. At what temperature is the density of water highest?
- A0°C
- B4°F
- C4K
- D4°C
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Answer: D) 4°C
Q28. The density of water when heated from 0°C to 100°C is ____
- Aincreases up to 4°C and then decreases.
- Bdecreases to 4°C and then increases
- Cincreases as the temperature rises
- Ddecreases as the temperature increases
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Answer: A) increases up to 4°C and then decreases.
Q29. What is the reason for the higher boiling point of water compared to hydrogen sulphide or hydrogen chloride?
- Apolar covalent bonding
- Bhydrogen bonding
- CWonderwalls Attractions
- DBipolar insulation
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Answer: B) hydrogen bonding
Q30. The chemical formula of water is_
- AC²
- BCo²
- CH²O
- DCH⁴
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Answer: C) H²O
Q31. Approximately what percentage of the world's land area is covered by water?
- A0.71
- B0.76
- C0.66
- D0.29
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Answer: A) 0.71
Q32. When salt is added to water, the boiling and freezing points of water increase.
- Awill increase
- Bwill decrease
- Cwill increase and decrease gradually
- Dwill gradually increase and decrease
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Answer: C) will increase and decrease gradually
Q33. In rural areas, water is disinfected by ____.
- Aby sodium chloride
- Bby chlorine
- Cby potassium permanganate
- Dby sodium sulphate
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Answer: B) by chlorine
Q34. potassium permanganate to water
- AMakes it germ-free
- BMakes it delicious
- CMakes it transparent
- DMakes it odor free.
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Answer: A) Makes it germ-free
Q35. Which of the following is a conductor of electricity?
- Arubber
- Bpure water
- Csalt water
- Dbenzene
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Answer: C) salt water
Q36. By which process can pure water be obtained from sea water?
- ABy distillation
- BBy compaction
- Cby evaporation
- Dby fractional distillation
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Answer: A) By distillation
Q37. Sea water contains more salt than rain water because _____.
- ARivers bring salts with them.
- BThere are salt rocks inside the sea.
- CThe atmosphere around the sea is salty.
- DAnimals living in the sea produce salt.
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Answer: A) Rivers bring salts with them.
Q38. Temporary hardness of water is due to the presence of
- Abicarbonates of calcium and magnesium
- BSulphates of calcium and magnesium
- CNitrates of calcium and magnesium
- Dchlorides of calcium and magnesium
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Answer: A) bicarbonates of calcium and magnesium
Q39. Permanent hardness in water is due to the presence of
- ASulphates of sodium and potassium
- BSulphates of magnesium and calcium
- Ccarbonates of sodium and magnesium
- Dbicarbonates of magnesium and calcium
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Answer: B) Sulphates of magnesium and calcium
Q40. .......... is used to remove permanent hardness of water.
- ABaking Soda
- BLime
- Cbleaching powder
- Dwashing soda
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Answer: D) washing soda
Q41. What is the function of heavy water in a nuclear reactor?
- ADecreasing the speed of neutrons
- Bincreasing the speed of neutrons
- CCooling the reactor
- Dstop nuclear activity
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Answer: A) Decreasing the speed of neutrons
Q42. Heavy water is used as a coolant in nuclear reactors. Heavy water
- AContains mineral rich water.
- BOzonated water is
- CWater containing heavy metal minerals is
- DWater contains heavy isotopes of hydrogen.
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Answer: D) Water contains heavy isotopes of hydrogen.
Q43. What is the chemical composition of heavy water?
- AH²O²
- BHO²
- CHDO
- DD²O
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Answer: D) D²O
Q44. The molecular weight of heavy water is ____
- A18
- B20
- C22
- D24
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Answer: B) 20
Q45. What happens in water that it is called 'heavy water'?
- Aheavy isotope of hydrogen
- Bheavy isotope of oxygen
- Catomic number of hydrogen atoms
- Dmolecular number of oxygen atoms
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Answer: A) heavy isotope of hydrogen
Q46. Heavy water is a type of_
- Acoolant is
- Bis dim
- Core is
- Dfuel is
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Answer: B) is dim
Q47. Used in bleaching hair
- ASulfuric good
- Boxalic acid
- Chydrogen peroxide
- Dheavy water
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Answer: C) hydrogen peroxide
Q48. It is used to restore the colours of old oil paintings.
- Asulfuric acid
- Boxalic acid
- Chydrogen peroxide
- Dheavy water
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Answer: C) hydrogen peroxide
Q49. Carbon is a_
- AMetal
- Bnonmetal
- Cmetalloid
- Dcompound
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Answer: B) nonmetal
Q50. The essential element of all organic compounds is ______.
- Anitrogen
- Boxygen
- CCarbon
- Dsulfur
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Answer: C) Carbon