401. Which of the following is the procedure for a biogas plant-

1. Fermentation
2. Reduction
3. Hydrogenation
4. Polymerization

Option “1” is correct.
The cow dung or gobar gas has a lot of energy which can be stored for a biogas plant by the process of fermentation.
402. Which one of the following is not an explosive:

1. Trinitrotoluene (TNT)
2. Trinitroglycerine
3. Cyclotrimethylene Trinitramine (RDX)
4. Nitrochloroform

Option “4” is correct.
Nitrochloroform is used as anaesthetics before the operation of the patient to make them unconscious. Other options are explosive.
403. The Nucleus of Helium has-

1. Only one neutron
2. Two protons
3. Two protons and two neutrons
4. One proton and two neutrons

Option “3” is correct.
Helium- (2He4) is a non-radioactive isotope of the element Helium. Its nucleus is identical to an alpha particle and consists of two protons and two neutrons.
404. Radioactivity is measured by-

1. Hydrometer
2. Geiger Counter
3. Seismometer
4. Ammeter

Option “2” is correct.
The Geiger-Muller Counter also called a Geiger Counter, is an instrument used for detection and measurement ionizing radiation.
405. Process of solid camphor into camphor vapour is called-

1. Vaporisation
2. Freezing
3. Melting
4. Sublimation

Option “4” is correct.
Solid camphor directly changes into camphor vapour and this process is called sublimation. The sublimation is the process in which some substances upon heating directly changes into vapour from and when cooled again directly turns into solid form.
406. Which one of the following is liquid at ordinary temperature?

1. Lead
2. Nickel
3. Mercury
4. Tin

Option “3” is correct.
Mercury is the only common metal which is liquid at ordinary temperature.
407. Percentage of Silver in German Silver is:

1. 1%
2. 5%
3. 0%
4. None of these

Option “3” is correct.
German Silver or Nickel silver is an alloy consisting 50% Copper, 35% Zinc and 15% Nickel. It doesn’t have silver.
408. In atom, neutron was discovered by:

1. J.J. Thomson
2. Chadwick
3. Rutherford
4. Newton

Option “2” is correct.
Neutron is a neutral particle which has no electrical charge. It was discovered by Chadwick in 1932.
409. Change of water into the vapour is called-

1. Natural
2. Physical
3. Chemical
4. Biological

Option “2” is correct.
Change of water into the vapour is called a physical change.
410. Which one of the following is the hardest metal?

1. Gold
2. Iron
3. Platinum
4. Silver

Option “3” is correct.
Among non-metals, diamond is the hardest whereas, among the metals, platinum is the hardest.

10 thoughts on “Chemistry”

  1. I Love chemical…it’s my favourite subject..mere iss mein se hmesha hi boht ache marks aate hai….and my interest is also in chemistry…

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