The pair of metals, which evolves hydrogen, when treated with caustic soda solution, is
(A) Cu, Zn
(B) Hg, Au
(D) Ni, Al
The hardest naturally occurring substance is
A smuggler could not carry gold by depositing iron on the gold surface, because
(A) gold has lower standard reduction potential than iron
(B) gold has higher standard reduction potential than iron.
(C) iron rusts
(D) gold in denser
The long form of Periodic Table consist of
(A) 8 horizontal and 7 vertical series
(B) 7 horizontal and 18 vertical series
(C) 7 horizontal and 7 vertical series
(D) 8 horizontal and 8 vertical series
In surgery, metal pins are used f
MatchColumn I with Column II and select the correct answer using the codes given below the columns .
Column I-(Alloy) Column II (Component)
A . Elinver 1 . Lead + tin
B . Solder 2 . Iron + nickel +Chromium
C . German silver 3 . Magnesium +aluminium
D . Magnalium 4 . Zinc + copper + nickel
(A) 2 1 4 3
(B) 2 3 4 1
(C) 4 3 2 1
(D) 4 1 2 3
By annealing, steel
(A) becomes soft
(B) becomes liquid
(C) becomes hard and brittle
(D) is covered with a thin film of Fe304
Consider the following statements
1 . The conductivity of electrolyte increases with rise in temperature.
2 . Voltameter is used in the process of electrolysis.
3 . Electrolysis of water is also called Hydrolysis .
Which of these statement(s) is/are correct?
(A) 1, 2 and 3
(B) 1 and 2
(C) 2 and 3
(D) 3 only
Transition metals are often paramagnetic owing to
(A) high mp and bp
(B) the presence of vacant orbital
(C) the presence of unpaired electrons
(D) malleability and ductility
When an alkali-metal reacts with water, which one of the following gases is produced?
(C) Hydrogen peroxide
Which one of the following is not an ore?
(B) Pig iron
(D) Zinc blende
MatchColumn I with Column II .
Column I Column II
A . Blue vitriol 1 . Sodium bicarbonate
B . Epsom salt 2 . Sodium hydroxide
C . Baking soda 3 . Magnesium sulphate
D . Caustic soda 4 . Copper sulphate
(A) 2 4 3 1
(B) 4 3 1 2
(C) 3 1 2 4
(D) 1 2 43
The electrochemical cell stops working after sometime because
(A) electrode potential of both the electrodes becomes zero
(B) one of electrodes completely vanishes
(C) electrode potential of both electrodes equalizes
(D) the reaction reverses its direction
In a period, the elements are arranged in the order of
(A) constant charges in the nucleus
(B) equal charges in the nucleus
(C) decreasing charges in the nucleus
(D) increasing charges in the nucleus
Solder is an alloy of
(A) tin and lead
(B) tin and copper
(C) tin, copper and zinc
(D) tin, lead and zinc
The ultra pure metal is obtained by
(C) zone refining
(D) None of these
Assertion (A) Gold occurs in native state.
Reason (R) Gold dissolves in aquilegia.
(A) Both A and R are individually true and R is the correct explanation of A.
(B) Both A and R are individually true, but R is not the correct explanation of A.
(C) A is true, but R is false.
(D) A is false, but R is true.