Class 11 Chemistry - Chapter Hydrogen NCERT Solutions | Write chemical reactions to show the amp

Justify the position of hydrogen in the periodic table on the basis of its electronic configuration.

Compare the structures of H₂O and H₂O₂.

Arrange the following

(i) CaH₂, BeH₂ and TiH₂ in order of increasing electrical conductance.

(ii) LiH, NaH and CsH in order of increasing ionic character.

(iii) H-H, D-D and F-F in order of increasing bond dissociation enthalpy.

(iv) NaH, MgH₂ and H₂O in order of increasing reducing property.

Discuss the principle and method of softening of hard water by synthetic ion-exchange resins.

What do you understand by the term “non-stoichiometric hydrides”? Do you expect this type of the hydrides to be formed by alkali metals? Justify your answer.

What is meant by 'demineralised' water and how can it be obtained?

What causes the temporary and permanent hardness of water?

How does H₂O₂ behave as a bleaching agent?

Why does hydrogen occur in a diatomic form rather than in a monoatomic form under normal conditions?

Describe the bulk preparation of dihydrogen by electrolytic method. What is the role of an electrolyte in this process?

How do you account for the formation of ethane during chlorination of methane?

What are hybridisation states of each carbon atom in the following compounds ?

(i) CH₂=C=O,

(ii) CH₃CH=CH₂,

(iii) (CH₃)₂CO,

(iv) CH₂=CHCN,

(v) C₆H₆

What will be the minimum pressure required to compress 500 dm³ of air at 1 bar to 200 dm³ at 30°C?

What are the common physical and chemical features of alkali metals?

Calculate the molecular mass of the following:
(i) H₂O
(ii) CO₂
(iii) CH₄

Assign oxidation number to the underlined elements in each of the following species:

(a) NaH₂PO₄

(b) NaHSO₄

(c) H₄P₂O₇

(d) K₂MnO₄

(e) CaO₂

(f) NaBH₄

(g) H₂S₂O₇

(h) KAl(SO₄)₂.12 H₂O

What is the basic theme of organisation in the periodic table?

Explain the formation of a chemical bond.

Choose the correct answer. A thermodynamic state function is a quantity
(i) used to determine heat changes
(ii) whose value is independent of path
(iii) used to determine pressure volume work
(iv) whose value depends on temperature only.

A liquid is in equilibrium with its vapour in a sealed container at a fixed temperature. The volume of the container is suddenly increased.
a) What is the initial effect of the change on vapour pressure?
b) How do rates of evaporation and condensation change initially?
c) What happens when equilibrium is restored finally and what will be the final vapour pressure?

Consider the reactions :

2 S₂O^2– _{3 (aq)} + I_2(s) → S₄ O^2– _6(aq) + 2I ^– _(aq)

S₂O^2– _3(aq) + 2Br_2(l) + 5 H₂O_(l) → 2SO^2–_4(aq) + 4Br^–_(aq) + 10H⁺_(aq)

Why does the same reductant, thiosulphate react differently with iodine and bromine ?

Which one of the following statements is incorrect in relation to ionization enthalpy?
(a) Ionization enthalpy increases for each successive electron.
(b) The greatest increase in ionization enthalpy is experienced on removal of electron from core noble gas configuration.
(c) End of valence electrons is marked by a big jump in ionization enthalpy.
(d) Removal of electron from orbitals bearing lower n value is easier than from orbital having higher n value.

How many significant figures should be present in the answer of the following calculations?

(i) 

(ii) 5 × 5.364

(iii) 0.0125 + 0.7864 + 0.0215

What is the total number of sigma and pi bonds in the following molecules?

(a) C₂H₂ (b) C₂H₄

Calculate the wavelength for the emission transition if it starts from the orbit having radius 1.3225 nm and ends at 211.6 pm. Name the series to which this transition belongs and the region of the spectrum.

How much energy is required to ionise a H atom if the electron occupies n = 5 orbit? Compare your answer with the ionization enthalpy of H atom (energy required to remove the electron from n =1 orbit).

Describe the change in hybridisation (if any) of the Al atom in the following reaction.

Calculate the total pressure in a mixture of 8 g of dioxygen and 4 g of dihydrogen confined in a vessel of 1 dm³ at 27°C. R = 0.083 bar dm³ K^–1 mol^–1.

Why does benzene undergo electrophilic substitution reactions easily and nucleophilic substitutions with difficulty?

Use Lewis symbols to show electron transfer between the following atoms to form cations and anions:

(a) K and S (b) Ca and O (c) Al and N.