21) Which is not a type of elements ?
a)Metals
b)Non Metals
c)Metalloids
d)Gases
22) Natural rubber is a polymer derived from ?
a)ethylene
b)propylene
c)isoprene
d)butadiene
23) Which one is an organic Acid ?
a)Sulphuric
b)Citric
c)Nitric
d)Phosphoric
24) Faraday’s Law is associated with
a)Reaction of gases
b)Pressure of gases
c)Electrolysis
d)Temperature and pressure
25) Permanent hardness of water is due to the presence of ?
a)Magnesium bicarbonate
b)Calcium bicarbonate
c)Sodium bicarbonate
d)Calcium sulphate
26) Mass number of a nucleus is
a) the sum of the number of neutrons and protons
b) always more than the atomic weight
c) always less than its atomic number
d) None of these
27) The organic reaction represented by equation CH3 – CH = O + H2NOH gives CH3 – CH – NH + H2O is an example of
a) an addition reaction
b) a condensation reaction
c) an oxidation reaction
d) an elimination reaction
28) The gas used in the manufacture of vanaspati from vegetable oil is
a) hydrogen
b) oxygen
c) nitrogen
d) carbon dioxide
29) The first metal used by man was
a) iron
b) copper
c) gold
d) bronze
30) The isomerism which exists between CH3CHCI2 and CH2CI. CH2CI is
a) chain isomerism
b) functional group isomerism
c) positional isomerism
d) metamerism