NCERT Class XI Chemistry The p-Block Elements Solutions
© examsnet.com
Question : 20
Total: 38
What happens when :
(a) Borax is heated strongly.
(b) Boric acid is added to water.
(c) Aluminium is treated with dilute NaOH.
(d)B F 3
(a) Borax is heated strongly.
(b) Boric acid is added to water.
(c) Aluminium is treated with dilute NaOH.
(d)
Solution:
(a) When powdered borax is heated strongly on the bunsen burner, it forms colourless transparent glassy (glass like) bead made of sodium metaborate and boric anhydride.
N a 2 B 4 O 7 . 10 H 2 O
N a 2 B 4 O 7
(b) It dissolves in water behaving as Lewis acid. It forms[ B ( O H ) 4 ] –
B ( O H ) 3 + H – O H [ B ( O H ) 4 ] – + H +
(c) Aluminium dissolves in NaOH solution to form a soluble complex and liberates hydrogen gas.
2 A l ( s ) + 2 N a O H ( a q ) + 6 H 2 O ( l )
+ 3 H 2 ( g )
(d)B F 3 N H 3
(b) It dissolves in water behaving as Lewis acid. It forms
(c) Aluminium dissolves in NaOH solution to form a soluble complex and liberates hydrogen gas.
(d)
© examsnet.com
Go to Question: