Showing posts with label CHEMISTRY. Show all posts
Showing posts with label CHEMISTRY. Show all posts

Saturday, 21 November 2015

10 COMMON QUESTION

Question 1
Neutrons were discovered by?
  Faraday
  J.J. Thomson
  Chadwick
  Dalton


It's 'Chadwick '
Sir James Chadwick was an English physicist who was awarded the 1935 Nobel Prize in Physics for his discovery of the neutron in 1932.
Question 2
Which of the following is used in preparation of dynamite?
  glycerol
  ethyl alcohol
  methyl alcohol
  glycol


It's 'glycerol '
Dynamite is an explosive material based on nitroglycerin, using diatomaceous earth or another adsorbent substance such as powdered shells or clay
Question 3
An alloy used in making heating elements for electric heating devices is _____?
  solder
  alloy steel
  nichrome
  German silver


It's 'nichrome '
Nichrome generally refers to any alloy of nickel, chromium, and often iron and other elements or substances. Nichrome alloys are typically used in resistance wire.
Question 4
Oxygen and ozone are _______.
  Allotropes
  Isomers
  Isotopes
  Isobars


It's 'Allotropes '
Allotropy is a behavior exhibited by certain chemical elements that can exist in two or more different forms, known as allotropes of that element. In each allotrope, the element's atoms are bonded together in a different manner. Thus, allotropes are different structural modifications of an element.
Question 5
Which hydrocarbon is mainly present in gobar gas?
  Butane
  Propane
  Methane
  Ethane


It's 'Methane '
Bio gas is produced from cattle dung in a bio gas plant commonly known as gobar gas plant through a process called digestion.
Question 6
A radioactive substance emits______?
  alpha particle
  beta particle
  gamma particle
  all of the three


It's 'all of the three '
Radioactive substances are continually producing three kinds of dangerous radiation, alpha particles, beta particles and gamma rays. These types of radiation are invisible to the naked eye and so you won't see a green glow.
Question 7
Which one among the following polymers is used for making bullet-proof material?
  Polyvinyl chloride
  Polystyrene
  Polyethylene
  Polyamide


It's 'Polyethylene '
A bullet-proof material is made of polyethylene. It is a higher grade of the plastic found in Tupperware.
Question 8
Hydrogen bomb is based on the principle of_______?
  nuclear fission
  nuclear fusion
  natural radioactivity
  artificial radioactivity


It's 'nuclear fusion '
Hydrogen bomb derives a large portion of its energy from the nuclear fusion of hydrogen isotopes.
Question 9
Which of the following is the lightest metal?
  Mercury
  Silver
  Lithium
  Lead


It's 'Lithium '
The lightest or least dense metal that is a pure element is lithium, which has a density of 0.534 g/cm3. This makes lithium nearly half as dense as water, so if lithium was not so reactive, a chunk of the metal would float on water.
Question 10
The inert gas abundantly found in widely distributed is_____?
  Xe
  Kr
  He
  Ar


It's 'Ar '
Argon (Ar) is the most prevalent of the noble gases in Earth's crust with the element composing 0.00015% of this crust.

Sunday, 1 November 2015

10 COMMON QUESTION ON CHEMISTRY

Question 1
In known elements, the maximum number is of ________?
  metals
  non-metals
  metalloids
  none of above


It's 'metals '
metal is a material (an element, compound, or alloy) that is typically hard, opaque, shiny, and has good electrical and thermal conductivity. About 91 of the 118 elements in the periodic table are metals.
Question 2
Which of the following is not a natural polymer?
  Wool
  Silk
  Cotton
  Teflon


It's 'Teflon '
Natural polymers occur in nature and can be extracted. They are often water-based. Examples of naturally occurring polymers are silk, wool, DNA, cellulose, cotton and proteins.
Question 3
Which one of the following petroleum refinery products has the lowest boiling point?
  Kerosene
  Gasoline
  Diesel
  Lubricating oil


It's 'Lubricating oil '
lubricating oil is the most commonly used lubricant because of its wide range of possible applications. The two basic categories of lube oil are mineral and synthetic. Mineral oils are refined from naturally occurring petroleum, or crude oil. Synthetic oils are manufactured polyalphaolefins, which are hydrocarbon-based polyglycols or ester oils.
Question 4
The photoelectric effect is described as the ejection of electrons from the surface of a metal when _____?
  It is heated
  It is placed in strong electric field
  Electron of suitable velocity impinge on it
  Light of suitable wavelength falls on it


It's 'Light of suitable wavelength falls on it '
The photoelectric effect refers to the emission, or ejection, of electrons from the surface of, generally, a metal in response to incident light. Energy contained within the incident light is absorbed by electrons within the metal, giving the electrons sufficient energy to be 'knocked' out of, that is, emitted from, the surface of the metal.
Question 5
Which one of the following chemical compounds is responsible for the stimulation of tear glands by the onion?
  phosphate compound
  nitrate compound
  sulphide compound
  chloride compound


It's 'sulphide compound '
When an onion is cut, certain (lachrymator) compounds are released causing the nerves around the eyes (lacrimal glands) to become irritated. These compounds consist of methionine and cystine that are part of the amino acid family. When an onion is sliced or diced, the onion's cells release these compounds into the air. When this occurs, "enzyme" works to alter the amino acids into lachrymator compounds. This form of sulfuric acid irritates the nerves around the eyes making them tear.
Question 6
The gas used to extinguish fire, is ____?
  neon
  nitrogen
  carbon dioxide
  carbon monoxide


It's 'carbon dioxide '
Fire needs three elements to prosper: fuel, oxygen and heat. The most common extinguishing agents like water, carbon dioxide, dry chemical and foams attack the fire physically to deprive the fire of one or more of the three critical elements needed for propagation. Halon differs in the way it puts out the fire.
Question 7
The charcoal used to decolourise raw sugar is __________?
  animal charcoal
  sugar charcoal
  coconut charcoal
  wood charcoal


It's 'coconut charcoal '
Charcoal is used as a decolourizing agent as it can adsorb colouring matter. It is used for decourizing sugar solutions, organic preparations, alcohol and petroleum products.
Question 8
Diamond, graphite, and fullerenes all forms of carbon, are examples of _______?
  catalysts
  isotopes
  structural isomers
  allotropes


It's 'allotropes '
Allotropes are different structural modifications of an element. The atoms of the element are bonded together in a different manner.
Question 9
A polymer which is used for making ropes and carpet fibres is ________.
  Polyacetylene
  Polypropylene
  Polyacrylonitrile
  PVC


It's 'Polyacetylene '
Polypropylene (PP), also known as polypropene, is a thermoplastic polymer used in a wide variety of applications including packaging and labeling, textiles (e.g., ropes, thermal underwear and carpets), stationery, plastic parts and reusable containers of various types, laboratory equipment, loudspeakers, automotive components, and polymer banknotes
Question 10
What among following is used to produce artificial rain?
  copper oxide
  carbon monoxide
  silver iodide
  silver nitrate


It's 'silver iodide '
Artificial rain is produced by spraying clouds with substances like Silver Iodide (costly) or cheaper ones like solid carbon dioxide (dry ice) or even finely powdered Sodium Chloride.