The most important ore of aluminium is

61.The most important ore of aluminium is

A.            bauxite                 B.            magnetite

C.            haematite           D.            monazite

Answer: Option A

62. 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

Answer: Option B

63.The number of electrons presents in H+ is

A.            zero                       B.            one

C.            two                        D.            three

Answer: Option A

64. The hottest part of the gas flame is known as

A.            luminous zone

B.            dark zone

C.            blue zone

D.            non-luminous zone

Answer: Option D

65. The human body is made up of several chemical elements; the element present in the highest proportion (65%) in the body is

A.            carbon                  B.            hydrogen

C.            oxygen                 D.            nitrogen

Answer: Option C

66. The isomerism which exists between CH3CHCI2 and CH2CI. CH2CI is

A.            chain isomerism

B.            functional group isomerism

C.            positional isomerism

D.            metamerism

Answer: Option C

67. The half life period of an isotope is 2 hours. After 6 hours what fraction of the initial quantity of the isotope will be left behind?

A.            1/6                         B.            1/3

C.            1/8                         D.            1/4

Answer: Option C

68. The number of waves made by an electron moving in an orbit having maximum magnetic quantum number is +3

A.            4              B.            5

C.            2              D.            zero

Answer: Option A