wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

Lake test of Al3+ ion is based on adsorption of blue litmus on solid surface of

A
Al2(CO3)3
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
Al(OH)3
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
C
AlCl3
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
Al metal
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is B Al(OH)3
Blue lake test:
To the Al3+ salt solution, add water, and then add ammonium chloride followed by ammonium hydroxide. White precipitate is formed which confirms Al3+ .
This precipitate is dissolved in HCl, a colorless solution is obtained.
Al(OH)3+3HClAlCl3+3H2O

Then 2 drops of blue litmus solution is added. Red color is obtained. And ammonium hydroxide is added to make the solution alkaline so that ammonium hydroxide is formed.
As soon as the solution becomes alkaline, blue floating precipitate is obtained.
Then the blue litmus solution is adsorbed on this aluminum hydroxide.
This is the principle for this test, Aluminum hydroxide is a good adsorbent, and therefore it adsorbs the blue litmus solution and gives this blue lake test.

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Group 2 Physical Properties
CHEMISTRY
Watch in App
Join BYJU'S Learning Program
CrossIcon