The correct statement among the following about H3BO3 is:
1. Monobasic and weak Lewis acid
2. Monobasic and weak Bronsted acid
3. Monobasic and strong Lewis acid
4. Tribasic and weak Bronsted acid
On the addition of mineral acid to an aqueous solution of borax, the compound formed is:
1. borodihydride
2. orthoboric acid
3. metaboric acid
4. pyroboric acid
Borax is prepared by treating boric acid with:
(1)
(2) NaCl
(3)
(4)
The main factor responsible for weak acidic nature of B-F bonds in is:
(1) large electronegativity of F
(2) three centred two electrons bonds in
(3) px- back bonding
(4) back bonding
Which among the following is a gas?
1.
2.
3.
4.
B-F bond order in is:
(1) 1
(2) 2
(3) 3
(4) 4/3
Aluminium reacts with nitrogen to form:
1. AlN
2.
3.
4.
Which metal is powdered, suspended in oil and used as paint?
(1) Fe
(2) Sn
(3) Ag
(4) Al
Aluminium metal is corroded in coastal places near to the sea, because protective oxide film:
(1) is removed by sea water
(2) reacts with sea water
(3) is attacked by salts present in sea water
(4) reacts with sand particles
Aluminium deposited as vapours on glass forms a good mirror, essentially because:
(1) it has better shine than Ag
(2) it does not scratch
(3) coating is much smoother
(4) it does not tarnish in air