JEE Advanced (Single Correct Type): Hydrogen | Chapter-wise Tests for JEE Main & Advanced PDF Download

Q.1. Which of the following is formed by the action of water on sodium peroxide?
(a) H₂
(b) N₂
(c) O₂
(d) CO₂

Correct Answer is option (c)
Na₂O₂ + H₂O → 2NaOH + 1/2O2

Q.2. The melting points of most of the solid substances increase with an increase of pressure acting on them. However, ice melts at a temperature lower than its usual melting point when the pressure is increased. This is because
(a) pressure generates heat
(b) the chemical bonds break under pressure
(c) ice is less denser than water
(d) ice is not a true solid

Correct Answer is option (c)
On increasing pressure, coordination number of ions in solids increases thus thereby increasing their melting point but in ice pressure does not increase the coordination number of oxygen & melting point does not increase but decrease under pressure.

Q.3. Activated hydrogen is obtained by
(a) electrolysis of heavy water
(b) reaction of water with heavy metals
(c) thermal decomposition of water
(d) passing silent electric discharge through hydrogen gas at low pressure

Correct Answer is option (d)

Hence, (D) is correct answer.

Q.4. The metal which gives hydrogen on treatment with acid as well as sodium hydroxide is
(a) Fe
(b) Zn
(c) Cu
(d) none of these

Correct Answer is option (b)

Zn + H₂SO₄ → ZnSO₄ + Na₂ZnO + H₂
Zn + 2NaOH → Na₂ZnO₂ + H₂
Hence (B)

Q.5. Polyphosphates are used as water softening agents because they
(a) Form soluble complexes with anionic species
(b) Precipitate anionic species
(c) Forms soluble complexes with cationic species
(d) Precipitate cationic species

Correct Answer is option (c)
Polyphosphates (sodium hexametaphosphates, sodium tripolyphosphate or STPP) from soluble complexes with Ca⁺², Mg⁺² present in hard water.

Q.6. When the same amount of zinc is treated separately with excess of sulphuric acid and excess of sodium hydroxide, the ratio of volumes of hydrogen evolved is
(a) 1: 1
(b) 1: 2
(c) 2: 1
(d) 9: 4

Correct Answer is option (a)
Zn + H₂SO₄ → ZnSO₄ + H₂
Zn + 2NaOH → Na₂ZnO₂ + H₂
The ratio of volumes of H₂ evolved in both the cases is 1: 1.

Q.7. The critical temperature of water is higher than that of O₂ because H₂O molecule has
(a) Fewer electrons than oxygen
(b) Two covalent bonds
(c) V-shape
(d) Dipole moment

Correct Answer is option (d)
Critical temperature of water is more than O₂ due to its dipole moment (Dipole moment of water = 1.84 D; Dipole moment of O₂ = zero D) .

Q.8. The reaction: Ag₂O + H₂O₂ → 2Ag + H₂O + O₂ takes place in
(a) basic medium
(b) bleaching agent
(c) neutral medium
(d) both in acidic and basic medium

Correct Answer is option (d)
H₂O₂ on oxidation gives O₂ only in basic medium.

Q.9. One mole of calcium phosphide on reaction with excess water gives
(a) One mole of phosphine
(b) Two moles of phosphoric acid
(c) Two moles of phosphine
(d) One mole of phosphorus pentaoxide

Correct Answer is option (c)

Q.10. When zeolite, which is hydrated sodium aluminium silicate, is treated with hard water the sodium ions are exchanged with
(a) H⁺ ions
(b) Ca²⁺ ions
(c) Mg²⁺ ions
(d) Both Ca²⁺ and Mg²⁺

Correct Answer is option (d)
Zeolite when treated with hard water exchange Cu⁺² and Mg⁺² ions (present in hard water) with Na⁺ ions.

Q.11. Pick the odd one out
(a) Sodium borohydride reacts very slowly with cold water.
(b) Sodium borohydride reacts very violently with cold water to produce H 2 .
(c) Solubility of sodium borohydride in water at 25°C is 10.05 g/mL.
(d) Melting point of sodium borohydride is 500°C.

Correct Answer is option (b)
Reaction of NaBH₄ with cold water is very slow. All other statements except (b) are correct.

Q.12. Which of the following is the true structure of H₂O₂?
(a)
(b)
(c)
(d)

Correct Answer is option (b)
Oxygen atom is sp³ hybridized having two large pair of electrons. Therefore the structure of hydrogen peroxide is

Q.13. Hydrogen will not reduce
(a) Heated cupric oxide
(b) Heated ferric oxide
(c) Heated stannic oxide
(d) Heated aluminium

Correct Answer is option (d)
H will not reduce heated Al₂O₃ .

Q.14. A hydride of nitrogen which is acidic is
(a) NH₃
(b) N₂H₄
(c) N₂H₂
(d) N₃H

Correct Answer is option (d)
N₃H (hydrazoic acid) is the acidic hydride of nitrogen

Q.15. HCl is added to following oxides. Which one would give H₂O₂
(a) MnO₂
(b) PbO₂
(c) BaO
(d) None of these

Correct Answer is option (d)
MnO₂ , PbO₂ and BaO will not give H₂O₂ with HCl.MnO₂ and PbO₂ will give Cl₂ and BaO will react with HCl to give BaCl₂ and water.

Q.16. Saline hydrides react explosively with water, such fires can be extinguished by
(a) Water
(b) Carbon dioxide
(c) Sand
(d) None of these

Correct Answer is option (c)
Fire due to action of water on saline hydrides cannot be extinguished with water or CO₂. These hydrides can reduce CO₂ at high temperature to produce O₂.

Q.17. Which of the following can not be oxidized by H₂O₂ ?
(a) KI + HCl
(b) O₃
(c) PbS
(d) Na ₂SO₃

Correct Answer is option (c)
O₃ is more powerful oxidizing agent than H₂O₂ . So H₂O₂ reduces O₃ to O₂.
O₂ + H₂O₂  → H₂O + 2O₂

Q.18. D₂O is preferred to H₂O , as a moderator, in nuclear reactors because
(a) D₂O slows down fast neutrons better
(b) D₂O has high specific heat
(c) D₂O is cheaper
(d) None of these

Correct Answer is option (d)
H₂O absorbs neutrons more than D₂O and this decreases the number of neutrons for the fission process.

Q.19. Heavy water is a compound of
(a) hydrogen& heavier isotope of oxygen
(b) heavier isotope of hydrogen & heavier isotope of oxygen
(c) oxygen& heavier isotope of hydrogen
(d) none of the above.

Correct Answer is option (d)
D₂O is heavy water.

Q.20. When electric current is passed through an ionic hydride in the molten state
(a) hydrogen is liberated at the anode
(b) hydrogen is liberated at the cathode
(c) no reaction takes place
(d) hydride ion migrates towards cathode

Correct Answer is option (d)
Ionic hydride contains H^- ion which liberates H₂ at the anode.