Hydrogen and its Compounds – Old Year Questions

1. An element X has four electrons in its outermost orbit. What will be the formula of its compounds with Hydrogen?

(a) X4H
(b) X4H4
(c) XH3
(d) XH4

[43rd B.P.S.C. (Pre) 1999]


2. According to weight, the percentage of Hydrogen in water (H2O), is –

(a) 44.45 %
(b) 5.55 %
(c) 88.89 %
(d) 11.11 %

[Uttarakhand U.D.A./L.D.A. (Mains) 2006]


3. One mole of hydrogen gas burns in excess of oxygen to give 290 KJ of heat. What is the amount of heat produced when 4g of Hydrogen gas is burnt under the same conditions?

(a) 145 Kj
(b) 290 Kj
(c) 580 Kj
(d) 1160 Kj

[I.A.S. (Pre) 1994]


4. Burning of hydrogen produces –

(a) Oxygen
(b) Ash
(c) Soil
(d) Water

[47th B.P.S.C. (Pre) 2005]


5. Which one of the following fuels causes minimum air pollution?

(a) Kerosene oil
(b) Hydrogen
(c) Coal
(d) Diesel

[U.P. Lower Sub. (Pre) 2015]


6. Heavy water is a type of –

(a) Coolant
(b) Moderator
(c) Ore
(d) Fuel

[U.P.P.C.S. (Pre) 1993]


7. The chemical formula of Heavy Water is :

(a) H2O
(b) D2O
(c) H2CO3
(d) H2S

[Jharkhand P.C.S. (Pre) 2003]


8. The chemical formula for heavy water is :

(a) H2O
(b) N2O
(c) D2O
(d) CuO
(e) None of the above/More than one of the above

[66th B.P.S.C. (Pre) (Re. Exam) 2020]


9. The substance used as moderator and coolant both, in nuclear reactors is :

(a) Ordinary water
(b) Heavy water
(c) Liquid Ammonia
(d) Liquid Hydrogen

[U.P. P.C.S. (Pre) 2016]


10. What is heavy water?

(a) Oxygen + Heavy Hydrogen
(b) Hydrogen + Oxygen
(c) Hydrogen + New Oxygen
(d) Heavy Hydrogen + Heavy Oxygen

[M.P.P.C.S. (Pre) 1991]


11. Heavy water is that water –

(a) The temperature of which is kept constant at 4°C
(b) In which insoluble salts of Calcium and Potassium are present
(c) In which isotopes takes place of Hydrogen
(d) In which isotopes takes place of Oxygen

[41st B.P.S.C. (Pre) 1996]


12. Heavy water –

(a) Contains more dissolved air
(b) Contains deuterium in place of Hydrogen
(c) Contains more dissolved minerals and salts
(d) Contains organic impurities

[U.P.P.C.S. (Mains) 2007]


13. Who among the following discovered heavy water?

(a) Heinrich Hertz
(b) H.C. Urey
(c) G.Mendel
(d) Joseph Priestly

[I.A.S. (Pre) 2008]


14. Heavy water has molecular weight :

(a) 18
(b) 20
(c) 36
(d) 54

[U.P. Lower Sub. (Mains) 2015]


15. Consider the following statements: Hard water is not suitable for
1. Drinking
2. Washing clothes with soap
3. Use in boilers
4. Irrigating crops
Which of these statements are correct?

(a) 1 and 2
(b) 2 and 3
(c) 1, 2 and 4
(d) 1, 2, 3 and 4

[I.A.S. (Pre) 2000]


16. Permanent hardness of water is due to –

(a) Chlorides and sulfates of Calcium and Magnesium
(b) Calcium bicarbonate sulfates
(c) Magnesium bicarbonate
(d) Chlorides of Silver and Potassium

[Uttarakhand P.C.S. (Pre) 2005, 40th B.P.S.C. (Pre) 1995]


17. The pH value for water is –

(a) Nearly zero
(b) Nearly 7
(c) 5 or less than 5
(d) 8.7 or more

[Uttarakhand P.C.S. (Pre) 2005]


18. The pH value of water is

(a) 4
(b) 7
(c) 12
(d) 18
(e) None of the above/More than one of the above

[66th B.P.S.C. (Pre) (Re. Exam) 2020, 65th B.P.S.C. (Pre) 2019]


19. Which is the purest form of water?

(a) Tap water
(b) Seawater
(c) Rainwater
(d) Distilled water

[M.P.P.C.S. (Pre) 2000]


20. Water is a good solvent of ionic salts because –

(a) It has a high boiling point
(b) It has a high dipole moment
(c) It has a high specific heat
(d) It has no color

[I.A.S. (Pre) 1994]


21. Water can dissolve more substances than any other liquid because :

(a) it is dipolar in nature
(b) it is a good conductor of heat
(c) it has a high value of specific heat
(d) it is an oxide of hydrogen

[I.A.S. (Pre) 2021]


22. Large quantities of drinking water is prepared from impure water by –

(a) Desalination
(b) Distillation
(c) Ion-exchange
(d) Decantation

[Uttarakhand P.C.S. (Pre) 2005]


23. Which gas is used in the purification of drinking water?

(a) Helium
(b) Chlorine
(c) Fluorine
(d) Carbon dioxide

[Jharkhand P.C.S. (Pre) 2013]


24. By which process the seawater can be converted into pure water?

(a) Deliquescence
(b) Efflorescence
(c) Electric separation
(d) Reverse osmosis

[R.A.S./R.T.S.(Pre) 2008]


25. The process used for transforming salty water into pure water is called –

(a) Deliquescence
(b) Efflorescence
(c) Electric separation
(d) Reverse osmosis

[U.P.P.C.S. (Mains) 2013]


26. By which process, Alum cleans the muddy water?

(a) Absorption
(b) Adsorption
(c) Coagulation
(d) Dialysis

[R.A.S./R.T.S.(Pre) 2000]


27. The gas used in the manufacture of Vanaspati Ghee from Vanaspati Oil is –

(a) Hydrogen
(b) Oxygen
(c) Nitrogen
(d) Carbon dioxide

[60th to 62nd B.P.S.C. (Pre) 2016,U.P.P.C.S. (Mains) 2013]


28. Which one of the following catalysts is used in the hydrogenation of vegetable oils?

(a) Zinc
(b) Platinum
(c) Nickel
(d) Iron

[U.P. P.C.S. (Mains) 2016, U.P.P.C.S. (Mains) 2010]