Chemistry Questions and Answers Part-6

1. The oil used in the froth floatation process is
a) coconut oil
b) olive oil
c) kerosene oil
d) pine oil

Answer: d
Explanation: The oil used in froth flotation process in pine oil, it is because it does not have affinity towards water and it easily attracts impurities and impurities can easily wash away.

2. The number of waves in n x 10th Bohr's orbit are
a) n2
b) n
c) n-2
d) n3

Answer: b
Explanation: The number of waves in n x 10th Bohr's orbit are n waves.

3.The mass of one Avogadro number of helium atom is
a) 1.00 gram
b) 4.00 gram
c) 8.00 gram
d) 4 x 6.02 x 1023 gram

Answer: d
Explanation: The mass of one Avogadro number of helium atom is 4 x 6.02 x 1023 gram.

4. The items amenable to detection by soft x-rays are
a) contrabands
b) lead in bullets
c) narcotics
d) genuine coins from counterfeit coins

Answer: d
Explanation: The items amenable to detection by soft x-rays are genuine coins from counterfeit coins.

5.The material which can be deformed permanently by heat and pressure is called a
a) thermoplastic
b) thermoset
c) chemical compound
d) polymer

Answer: b
Explanation: The material which can be deformed permanently by heat and pressure is called thermoset.

6. The iron ore magnetite consists of
a) Fe2O3
b) Fe3OH4
c) FeCO3
d) 3Fe2O3 .3H2O

Answer: a
Explanation: The iron ore magnetite consists of Fe2O3.

7. The ionisation energy of hydrogen atom in the ground state is x KJ. The energy required for an electron to jump from 2nd orbit to 3rd orbit is
a) 5x/36
b) 5x
c) 7.2 x
d) x/6

Answer: a
Explanation: 5x/36

8. The major constituent of air is
a) carbon dioxide
b) nitrogen
c) Oxygen
d) hydrogen

Answer: b
Explanation: Below a height of about 86 kilometers, the three main gaseous elements, which together account for about 99.9% of the total atmosphere, exist in essentially constant proportion to the total: nitrogen comprises 78% of air by volume, oxygen comprises 21% of air by volume, and argon comprises another 0.9%.

9. The main chemical constituent of clay is
a) silicon oxide
b) aluminium borosilicate
c) zeolites
d) aluminium silicate

Answer: d
Explanation: Aluminium silicate is the main Chemical constituent of clay.

10. The mineral containing both magnesium and calcium is
a) magnesite
b) calcite
c) carnallite
d) dolomite

Answer: d
Explanation: The mineral containing both magnesium and calcium is Dolomite.