11) The metal that is usually extracted from sea water is
a) Ca
b) Na
c) K
d) Mg
12) Variable valency is exhibited by
a) tin
b) Barium
c) Sodium
d) Zinc
13) The hottest part of the gas flame is known as
a) luminous zone
b) dark zone
c) blue zone
d) non-luminous zone
14) Which of the following is not a metal?
a) Helium
b) Cobalt
c) Lithium
d) Sdium
15) The molecular formula of phosphorous is
a) P1
b) P2
c) P3
d) P4
16) The formula C6H5-CO-CH3 represents
a) Acetone
b) Acetic acid
c) Acetophenone
d) Phenyl acetate
17) Which of the following is not an ally of Copper?
a) Gun Metal
b) Solder
c) Brass
d) Bronze
18) Which acid is present in lemon ?
a)marlic acid
b)citric acid
c)lactic acid
d)tartaric acid
19) A maximum of carbon monoxide and hydrogen is
a) gobar gas
b) water gas
c) producer gas
d) coal gas
20) Water drops are spherical because of ?
a)viscosity
b)density
c)polarity
d)surface tension