Class 11 Chemistry - Chapter Classification of Elements and Periodicity in Properties NCERT Solutions | Considering the elements B, C, N, F, and

Write the general outer electronic configuration of s-, p-, d- and f- block elements.

Considering the elements B, Al, Mg, and K, the correct order of their metallic character is:
(a) B > Al > Mg > K
(b) Al > Mg > B > K
(c) Mg > Al > K > B
(d) K > Mg > Al > B

What is the basic difference between the terms electron gain enthalpy and electronegativity?

What do you understand by isoelectronic species? Name a species that will be isoelectronic with each of the following atoms or ions.

(i) F^–

(ii) Ar

(iii) Mg²⁺

(iv) Rb⁺

Assign the position of the element having outer electronic configuration

(i) ns² np⁴ for n = 3 (ii) (n - 1)d² ns² for n = 4, and (iii) (n - 2) f⁷ (n - 1)d¹ ns² for n = 6, in the periodic table.

How does atomic radius vary in a period and in a group? How do you explain the variation?

Use the periodic table to answer the following questions.
(a) Identify an element with five electrons in the outer subshell.
(b) Identify an element that would tend to lose two electrons.
(c) Identify an element that would tend to gain two electrons.
(d) Identify the group having metal, non-metal, liquid as well as gas at the room temperature.

Considering the elements F, Cl, O and N, the correct order of their chemical reactivity in terms of oxidizing property is:
(a) F > Cl > O > N
(b) F > O > Cl > N
(c) Cl > F > O > N
(d) O > F > N > Cl

On the basis of quantum numbers, justify that the sixth period of the periodic table should have 32 elements.

Write the atomic number of the element present in the third period and seventeenth group of the periodic table.

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

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?

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

The following data are obtained when dinitrogen and dioxygen react together to form different compounds:

Mass of dinitrogen         Mass of dioxygen

(i) 14 g                                  16 g

(ii) 14 g                                 32 g

(iii) 28 g                                 32 g

(iv) 28 g                                 80 g

(a) Which law of chemical combination is obeyed by the above experimental data?Give its statement.

(b) Fill in the blanks in the following conversions:

(i) 1 km = ...................... mm = ...................... pm

(ii) 1 mg = ...................... kg = ...................... ng

(iii) 1 mL = ...................... L = ...................... dm3

Describe the hybridisation in case of PCl₅. Why are the axial bonds longer as compared to equatorial bonds?

Express the following in the scientific notation:
(i) 0.0048
(ii) 234,000
(iii) 8008
(iv) 500.0
(v) 6.0012

Propanal and pentan-3-one are the ozonolysis products of an alkene? What is the structural formula of the alkene?

If the velocity of the electron in Bohr’s first orbit is 2.19 × 10⁶ ms^–1, calculate the de Broglie wavelength associated with it.

What is the number of photons of light with a wavelength of 4000 pm that provide 1 J of energy?

Identify the functional groups in the following compounds

What are the oxidation number of the underlined elements in each of the following and how do you rationalise your results ?

(a) KI₃

(b) H₂S₄O₆

(c) Fe₃O₄

(d) CH₃CH₂OH

(e) CH₃COOH

Is there any change in the hybridisation of B and N atoms as a result of the following reaction?

BF₃ + NH₃ → F₃B.NH₃

Consider the elements:

Cs, Ne, I and F

(a) Identify the element that exhibits only negative oxidation state.

(b) Identify the element that exhibits only postive oxidation state.

(c) Identify the element that exhibits both positive and negative oxidation states.

(d) Identify the element which exhibits neither the negative nor does the positive oxidation state.