Intermediate First Year Chemistry>Chapter 2 - Classification of Elements and Periodicity in Properties>QUESTIONS>Q 75

MEDIUM

11th Telangana Board

IMPORTANT

Earn 100

What is valency of an element? How does it vary with respect to hydrogen in the third period?

Important Questions on Classification of Elements and Periodicity in Properties

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11th Telangana Board

IMPORTANT

Intermediate First Year Chemistry>Chapter 2 - Classification of Elements and Periodicity in Properties>QUESTIONS>Q 76

What is diagonal relationship? Give a pair of elements having diagonal relationship. Why do they show this relation?

EASY

11th Telangana Board

IMPORTANT

Intermediate First Year Chemistry>Chapter 2 - Classification of Elements and Periodicity in Properties>QUESTIONS>Q 77

What is lanthanide contraction? What are its consequences?

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11th Telangana Board

IMPORTANT

Intermediate First Year Chemistry>Chapter 2 - Classification of Elements and Periodicity in Properties>QUESTIONS>Q 78

The first

IP

of lithium is

5.41 eV

and electron affinity of

Cl

is

- 3.61 eV

. Calculate

∆ H

in

kJ {mol}^{- 1}

for the reaction:

Li (g) + Cl (g) \to Li {(g)}^{+} + Cl {(g)}^{-}

.

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IMPORTANT

Intermediate First Year Chemistry>Chapter 2 - Classification of Elements and Periodicity in Properties>QUESTIONS>Q 79

How many

Cl

atoms can you ionise in the process

Cl \to {Cl}^{+} + e^{-}

by the energy liberated for the process

Cl + e^{-} \to {Cl}^{-}

for one Avogadro's number of atoms? Given,

IP = 13.0 eV

and

EA = 3.60 eV

. Avogadro's number

= 6 \times 10^{23}

.

EASY

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IMPORTANT

Intermediate First Year Chemistry>Chapter 2 - Classification of Elements and Periodicity in Properties>QUESTIONS>Q 80

The electron affinity of chlorine is

3.7 eV

. How much energy in

kcal

is released when

2 g

of chlorine atoms is completely converted to

{Cl}^{-}

ions in the gaseous state?

(1 eV = 23.06 kcal)

.

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11th Telangana Board

IMPORTANT

Intermediate First Year Chemistry>Chapter 2 - Classification of Elements and Periodicity in Properties>QUESTIONS>Q 81

Discuss the classification of elements by Mendeleev.

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11th Telangana Board

IMPORTANT

Intermediate First Year Chemistry>Chapter 2 - Classification of Elements and Periodicity in Properties>QUESTIONS>Q 82

From a study of properties of neighbouring elements, the properties of an unknown element can be predicted-Justify with an example.

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11th Telangana Board

IMPORTANT

Intermediate First Year Chemistry>Chapter 2 - Classification of Elements and Periodicity in Properties>QUESTIONS>Q 83

Discuss the construction of long form periodic table.