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Q1. Oxidation state of hydrogen in H₂O and H₂O₂ respectively is:

• +1 and +0.5
• +1 in both
• -1 in both
• +1 and -1

Solution

Oxidation state of hydrogen in H₂O and H₂O₂ is +1.

Q2. On an industrial scale, H₂O₂ is prepared by oxidation of:

• 2-ethylanthraquinone
• 2-ethylanthraquinine
• 2-ethylanthraquinol
• 2-methylanthraquinol

Solution

H₂O₂ is prepared industrially by oxidation of 2-ethylanthraquinol as it is very cheap.

Q3. Water has maximum density at:

• 4^oC
• 4K
• 0^oC
• 1^oC

Solution

Density of water is maximum at 4^oC. The increase in temperature results in increase in kinetic energy so increasing volume and hence decreasing density.

Q4. Hydrogen differs from alkali metals as it:

• Has one electron in its valency shell
• Does not possess metallic character
• Can form compounds with non-metals
• Halides of hydrogen ionizes  in aqueous solution

Solution

Hydrogen differs from alkali metals as it does not possess metallic character .

Q5. Electron rich hydrides are formed by compounds of group:

• 15-17
• 14
• 7-8
• 13

Solution

Electron rich hydrides are formed by compounds of group   15-17. Since there is a  presence of lone pair of electrons,it results in the formation of hydrogen bond between the molecules.

Q6. From the following statements regarding H₂O₂, choose the incorrect statement:

• It can act only as an oxidizing agent.
• It decomposes on exposure to light.
• It has to be stored in plastic or wax lined glass bottles in dark.
• It is miscible in water in all proportions and forms a hydrate.

Solution

H₂O₂ can act both as an oxidising as well as a reducing agent as it can be oxidised and reduced.

Q7. Like alkali metals hydrogen also forms:

• Oxides,halides and sulphides
• Metallic bonding
• Homolytic cleavage
• Optical isomers

Solution

Like alkali metals, hydrogen also forms oxides,halides and sulphides.

Q8. Hydrides are classified as:

• Non-ionic,non-covalent and non-metallic
• Ionic,covalent and metallic
• Non-covalent,non-molecular and stoichiometric
• Non-molecular,non-metallic and stoichiometric

Solution

Hydrides are classified into three categories: Ionic Covalent  Metallic hydrides

Q9. Which of the following statements is correct?

• Permanent hardness of water can be removed by boiling.
• Temporary and permanent hardness of water can be removed by boiling.
• Neither temporary nor permanent hardness of water can be removed by boiling.
• Temporary hardness of water can be removed by boiling.

Solution

Temporary hardness of water can be removed by boiling.

Q10. Largest single use of dihydrogen is in the:

• Manufacture of HCl
• Manufacture of ammonia
• Manufacture of nylon
• Manufacture of refined oil

Solution

Largest single use of dihydrogen is in the manufacture of ammonia.

Q11. Element that is found abundantly in the universe and is the principal element of solar atmosphere is:

• Helium
• Dihydrogen, H₂
• Sodium
• Aluminium

Solution

Element that is found abundantly in the universe is Dihydrogen,H₂.       

Q12. Three isotopes of hydrogen are:

• Helium-2,Helium-3 and Helium-4
• Deuterium,tritium and protium
• ¹⁴⁰Ho ,¹⁴¹Ho  and ¹⁴²Ho
• Graphite, fullerene and diamond

Solution

 Three isotopes of hydrogen are deuterium,tritium and protium.  

Q13. H₂O₂ can be used as:

• Bleaching agent
• Oxidizing agent
• Antiseptic
• All the above

Solution

H₂O₂ can be used as bleaching agent, oxidizing agent and as an antiseptic.

Q14. The sum of number of neutrons and protons in tritium is:

• 3
• 4
• 5
• 6

Solution

Sum of number of neutrons and protons represents mass number. Tritium   () has 1 proton and 2 neutrons.

Q15. In terms of ionization enthalpy ,hydrogen resembles more with

• Carbonyl compound
• Halogens
• Isopropyl free radical
• Ethyl free radical

Solution

In terms of ionization enthalpy ,hydrogen resembles more with halogens as the ionisation energies are comparable.

Q16. NaH  when added to water produces a large amount of energy. The hydride will be:

• Interstitial hydride
• Covalent hydride
• Ionic hydride
• All of the above

Solution

Saline or ionic hydrides react violently with water producing hydrogen gas and large amount of energy.

Q17. Which of the following can remove permanent hardness of water?

• Na₂CO₃
• Na₆P₆O₁₈
• Ion exchange resin
• All of the above

Solution

Permanent hardness of water can be treated by Na₂CO_{3 ,}Na₆P₆O₁₈ and ion exchange resin.

Q18. Dihydrogen under certain reaction conditions combines with all elements except:

• Noble gases
• Non-metals
• Metals
• Halogens

Solution

Dihydrogen under certain reaction conditions combine with all elements except noble gases.

Q19. Which of the following is an incorrect statement?

• Temporary hardness of water can be removed by boiling.
• Temporary hardness of water is due to bicarbonates of Ca and Mg.
• Temporary hardness of water is due to chlorides and sulphates of Ca and Mg.
• Permanent hardness of water is due to chlorides and sulphates of Ca and Mg.

Solution

Temporary hardness of water is not due to chlorides and sulphates of Ca and Mg but because of bicarbonates of Ca and Mg.

Q20. The volume of a "10 volume solution"  of  H₂O₂  required to liberate 500mL O₂ at N.T.P, is:

• 50 mL
• 25 mL
• 100 mL
• 125 mL

Solution

10 volume solution of H₂O₂ means that 1L of this H₂O₂ will give 10 L of oxygen at NTP.

Q21. Which of the following contains interstitial water?

• FeSO₄
• BaCl₂
• CuSO₄
• CrCl₂

Solution

BaCl₂ contains interstitial water as BaCl₂.2H₂O.

Q22. Reaction of granulated zinc with dil HCl results in formation of:

• HD
• Tritium
• Dihydrogen
• Protium

Solution

Reaction of granulated zinc with dil HCl results in formation of  dihydrogen.  

Q23. Water is:

• Acidic
• Basic
• Alkaline
• Amphoteric

Solution

Water reacts with both acids as well as bases. Thus,it is amphoteric as it can act as an acid as well as a base.

Q24. Clark's method of water softening uses:

• Na₂CO₃
• Ca(OH)₂
• Ion exchange resin
• Na₆P₆O₁₈

Solution

In Clark's method of water softening, hard water is treated with Ca(OH)₂ (Slaked lime).

Q25. With dinitrogen,dihydrogen forms:

• Ethanal
• Ammonia
• Silicon
• Diamond

Solution

With dinitrogen, dihydrogen forms ammonia.

Q26. Of all the isotopes of hydrogen, which one is highly radioactive?

• HD
• Tritium
• Deuterium
• Protium

Solution

Of all the isotopes of hydrogen, tritium is highly radioactive.

Q27. Electron-rich hydrides have excess electrons that are present as:

• Free radical
• Lone pairs
• Chain pair
• Dot structure

Solution

 Electron rich hydrides have excess electrons that are present as lone pair.

Q28. Number of neutrons in Tritium are:

• 4
• 3
• 2
• 1

Solution

Number of neutrons = Mass number - Atomic number                              =3-1                              =2

Q29. Tritium is an isotope of the element:

• Hydrogen
• Helium
• Chlorine
• Sodium

Solution

 Tritium is an isotope of the element hydrogen.

Q30. H₂O₂ can act as:

• Oxidizing agent
• Reducing agent
• Both oxidizing and reducing agent
• Neither oxidizing nor reducing agent