S Block Elements Question 3
Question 3 - 24 January - Shift 2
Identify the correct statements about alkali metals.
A. The order of standard reduction potential $(M^{+} \mid M)$ for alkali metal ions is $Na>Rb>Li$.
B. CsI is highly soluble in water.
C. Lithium carbonate is highly stable to heat.
D. Potassium dissolved in concentrated liquid ammonia is blue in colour and paramagnetic.
E. All the alkali metal hydrides are ionic solids.
Choose the correct answer from the options given below
(1) A, B, D only
(2) C and E only
(3) A and E only
(4) A, B and E only
Show Answer
Answer: (3)
Solution:
Formula: Formula
(1) $Na>Cs>Li-$ true {If considered with sign }
The low solubility of CsI is due to smaller hydration enthalpy of it’s two ions
$Li_2 CO_3$ is highly stable to heat - false
In Conc. $NH_3, K$ formed blue solution - true
