HARD
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Assertion A : Alkali metals are soft and have low melting and boiling points.

Reason (R) : This is because interatomic bonds are weak.

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Important Questions on Elements of Group 1 and Group 2

MEDIUM

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R. Assertion A : LiF is sparingly soluble in water. Reason R : The ionic radius of Li+ ion is smallest among its group members, hence has least hydration enthalpy.

In the light of the above statements, choose the most appropriate answer from the options given below.

HARD

Match List-I with Match List-II

  List-I
(Metal)
  List-II
(Emitted light wavelength nm)
(A) Li (I) 670.8
(B) Na (II) 589.2
(C) Rb (III) 780.0
(D) Cs (V) 455.5

Choose the most appropriate answer from the options given below

EASY

The correct order of hydration enthalpies is

(A) K+
(B) Rb+
(C) Mg2+
(D) Cs+
(E) Ca2+

Choose the correct answer from the options given below:

EASY
What is the colour of the flame on heating potassium in the flame of a Bunsen burner?
MEDIUM

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Lithium salts are hydrated.
Reason (R) : Lithium has higher polarising power than other alkali metal group members.

In the light of the above statements, choose the most appropriate answer from the options given below :

MEDIUM
Match List - I with List - II.
List-I (Salt) List-II (Flame colour wavelength)
(a) LiCl (i) 455.5 nm
(b) NaCl (ii) 670.8 nm
(c) RbCl (iii) 780.0 nm
(d) CsCl (iv) 589.2 nm

Choose the correct answer from the options given below:

HARD

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R:

Assertion A: Metallic sodium dissolves in liquid ammonia giving a deep blue solution, which is paramagnetic.
Reasons R: The deep blue solution is due to the formation of amide.

In the light of the above statements, choose the correct answer from the options given below:

MEDIUM
Consider the following ionization enthalpies of two elements 'A' and 'B'.
 
Element Ionization enthalphy kJ/mol
  1st 2nd 3rd
A 899 1757 14847
B 737 1450 7731


Which of the following statements is correct?
EASY
The correct order of electrical conductivity of alkali metals ions in their aqueous solution for Cs+, K+, Na+ and L+ is
EASY
Which of the following alkali metals has the lowest melting point?
MEDIUM
The correct order of hydration enthalpies of alkali metal ions is: