Q.1. Which among the following element is an essential constituent of acids?
[A] Nitrogen
[B] Hydrogen
[C] Oxygen
[D] Helium
Answer: B [Hydrogen]
Q.2. What is the maximum stress after which the wire breaks called as?
[A] Tensile strength
[B] Shear strength
[C] Bulk strength
[D] Hooke’s strength
Answer: A [Tensile strength]
Notes:
The maximum stress after which the wire begin to flow and breaks, is called breaking stress or tensile strength. The force by application of which the wire breaks is called the breaking force.
Q.3. Which of the following is correct about electrolytic refining?
[A] Strip of pure metal is used as anode
[B] Strip of pure metal is used as cathode
[C] Copper cannot be refined using an electrolytic method
[D] All of the above
Answer: B [Strip of pure metal is used as cathode]
Notes:
In electrolytic refining, the impure metal is made to act as anode. A strip of the same metal in pure form is used as cathode. Copper is generally refined using an electrolytic method.
Q.4. What do we call the polymers which have strong intermolecular forces between the chains?
[A] Fibres
[B] Elastomers
[C] Thermoplastics
[D] None of the above
Answer: A [Fibres]
Notes:
Fibres are the polymers which have strong intermolecular forces between the chains. These forces are either hydrogen bonds or dipole-dipole interactions.
Q.5. What is the sweetness value of Aspartame in comparison to the cane sugar?
[A] 10
[B] 100
[C] 200
[D] 500
Answer: B [ 100]
Notes:
Aspartame is the most successful and widely used artificial sweetener. It is roughly 100 times as sweet when compared to the cane sugar. It is methyl ester of dipeptide formed from aspartic acid and phenylalanine.
Q.6. When a tube light breaks, a cracking sound is produced because __?
[A] Pressure inside the lamp is less than atmospheric pressure
[B] Pressure inside the lamp is more than atmospheric pressure
[C] The lamp is filled with reactive gases
[D] The lamp is filled with mercury vapour
Answer: A [Pressure inside the lamp is less than atmospheric pressure ]
Notes:
A fluorescent lamp tube is filled with a gas containing low pressure mercury vapor and argon, xenon, neon, or krypton. The pressure inside the lamp is around 0.3% of atmospheric pressure.
Q.7. What is the electron configuration of Radium?
[A] 6s2
[B] 7s2
[C] 7s2 7p6
[D] 7s2 7p4
Answer: B [7s2]
Notes:
Radium is a chemical element with the symbol Ra and atomic number 88. It is the sixth element in group 2 of the periodic table, also known as the alkaline earth metals.The electron configuration (short form) of radium is [Rn]7s2 .
Q.8. Which orbital will have lower energy if two orbitals have the same value of (n+l)?
[A] orbital with lower value of n
[B] orbital with lower value of l
[C] orbital with lower value of (n-l)
[D] None of the above
Answer: A [orbital with lower value of n]
Notes:
If two orbitals have the same value of (n+l) then orbital with lower value of n will have lower energy. Also, energies of the orbitals in the same subshell decrease with increase in atomic number.
Q.9. Which of the following polymer is obtained by the condensation reaction between ethylene glycol and terephthalic acid?
[A] Terelene
[B] PMMC
[C] PVC
[D] None of the above
Answer: A [Terelene]
Notes:
Terelene is a polymer obtained by the condensation reaction between ethylene glycol and terephthalic acid. It is widely used in making wash and wear fabrics as it has low absorbing power.
Q.10. What is the use of iodoform?
[A] It helps in reducing fever
[B] It is used to induce sleep
[C] It is used as an antiseptic for wounds
[D] It is used to reduce acidity
Answer: C [ It is used as an antiseptic for wounds]
Notes:
Iodoform is used as an antiseptic for wounds. Iodoform is also known as tri-iodomethane, carbon triiodide, and methyl triiodide. It is also used as a disinfectant.
Q.11. Which of the following is an anti-knocking compound that has been phased out in many countries so far?
[A] Lead tetrachloride
[B] Tetra Ethyl Lead
[C] Ethyl acetate
[D] None of the above
Answer: B [Tetra Ethyl Lead ]
Notes:
Tetra Ethyl Lead (TEL) is one such component that is added to petrol to reduce its tendency to ping’ under compression. TEL breaks down to lead at upper cylinder temperatures. Lead atoms spread around and combining with the free radicals and slowing down the reaction. However,Leaded’ petrol was a grave danger to the environment, as lead is a poison when it is absorbed into the body.
Q.12. Which of the following is NOT correct about the use of Quick lime?
[A] Manufacturing of cement
[B] Manufacture of sodium carbonate
[C] Purification of sugar
[D] used to extinguish fire
Answer: D [used to extinguish fire]
Notes:
(i) It is an important primary material for manufacturing cement and is the cheapest form of alkali. (ii) It is used in the manufacture of sodium carbonate from caustic soda. (iii) It is employed in the purification of sugar and in the manufacture of dye stuffs.
Q.13. Which of the following is correct about the properties of the elements as per the Mendeleev’s Periodic Law?
[A] they are a periodic function of the element’s atomic number
[B] they are a periodic function of the element’s atomic weight
[C] they don’t depend on the element’s atomic weight
[D] they are same for every 4th element
Answer: B [they are a periodic function of the element’s atomic weight]
Notes:
As per Mendeleev’s Periodic Law, the properties of the elements are a periodic function of their atomic weights.
Q.14. Which of these polymers is used for controlled drug release in the body?
[A] PLA
[B] PHBV
[C] PGA
[D] PCL
Answer: B [PHBV]
Notes:
PHBV is a copolymer of 3 – hydroxy butanoic acid, and (3 – hydroxypentanoic acid). It is used in controlled drug release in the body as the drug put in PHBV capsule is released after this polymer is degraded by enzymatic action.
Q.15. Which of the following gas is also known as laughing gas?
[A] Nitrous oxide
[B] Nitrogen dioxide
[C] Nitrogen hydroxide
[D] Nitrogen peroxide
Answer: A [ Nitrous oxide]
Notes:
Nitrous oxide, commonly known as laughing gas is a colourless non-flammable gas, with a slight metallic scent and taste. It is also used in surgery and dentistry, for its anesthetic and pain reducing effects.
Q.16. Which among the following was first human-made plastic?
[A] Bakelite
[B] Polyethene
[C] Celluloid
[D] Nylon
Answer: C [Celluloid]
Notes:
he first human-made plastic was made by Alexander Parkes in 1855, when he synthesized celluloid. The new discovery found its use in photographic films, but it could not be used for making containers or insulators for electric circuits.
The first true plastic was made in 1909 by Leo Baekeland, who synthesized Bakelite. The hard plastic could be used to make handles, auto parts, etc. The First World War witnessed improvements in the manufacture of polystyrene and polyvinyl chloride, which found use in plumbing equipment and electric wire insulation. Nylon was synthesized in the 1930s. By 1950, plastics became quite popular and as a result we can see them everywhere today
Q.17. What is the general outer electron configuration of Group 13 elements?
[A] ns2 np2
[B] ns2
[C] ns2 np1
[D] ns2 np3
Answer: C [ns2 np1]
Notes: ns2 np1
Q.18. Who gave the law of octaves for arrangement of elements?
[A] Lothar Meyer
[B] Dmitri Mendeleev
[C] John Alexander Newlands
[D] Johann Dobereiner
Answer: C [John Alexander Newlands]
Notes:
Newland law of octaves states that If the elements are arranged in order of their increasing atomic weights, every 8th element had similar properties to the first one. It was similar as the first and eighth note in music.
Q.19. Which of the polymers is formed due to the reaction of hexamethylene diamine and adipic acid?
[A] PVC
[B] Polypropylene
[C] Teflon
[D] Nylon 6,6
Answer: D [Nylon 6,6]
Notes:
Nylon 6,6 is a synthetic polymer which can be formed due to the reaction of hexamethylene diamine and adipic acid.
Q.20. Which of the following scientists is known for using electrolysis to isolate and discover many elements?
[A] Humphry Davy
[B] James Burrow
[C] John Pringle
[D] Davies Gilbert
Answer: A [Humphry Davy]
Notes:
Sir Humphry Davy (1778 – 1829) is best known for using electrolysis to isolate and discover many elements. He is credited with isolating or discovering sodium, calcium, boron, barium, magnesium, iodine, chlorine, and potassium. He also invented a safety lamp for miners called the Davy lamp. He also named nitrous oxide as laughing gas.
Q.21. Consider the following Statements:
- Radon is the heaviest gas.
- statine is the rarest element on the earth.
- Graphite which is a non-metal is also an electrical conductor.
Which among the above Statement(s) is/are correct?
[A] Only 2
[B] 1 and 2
[C] 2 and 3
[D] 1, 2 and 3
Answer: D [1, 2 and 3]
Notes:
Radon is a chemical element with the symbol Rn and atomic number 86. It is a radioactive, colorless, odorless, tasteless noble gas. It is the heaviest gas.
Astatine is a chemical element with the symbol At and atomic number 85. It is the rarest naturally occurring element in the Earth’s crust, occurring only as the decay product of various heavier elements.
Graphite on the other hand, although also only made up of carbon atoms, is the only non-metal that can conduct electricity. This is because only 3 of the available valence electrons form covalent bonds leaving 1 spare electron, which then becomes delocalised.
Q.22. What is water gas?
[A] mixture of CO and H2
[B] mixture of CO and H2O
[C] mixture of CO2 and H2
[D] Carbon mono-oxide
Answer: A [mixture of CO and H2]
Notes:
The mixture of CO and H2 produced is known as water gas or synthesis gas.
Q.23. What happens to the effective nuclear charge as we move from left to right in the periodic table?
[A] It increases
[B] it decreases
[C] It remains constant
[D] It increases till 4th group then decreases
Answer: A [It increases]
Notes:
The effective nuclear charge of an element increases as we move from left to right in the periodic table.
Q.24. Which of the following metals are the constituents of German silver?
[A] Nickel
[B] Copper
[C] Zinc
[D] All of the above
Answer: D [All of the above]
Notes:
German Silver is an alloy of copper, zinc and nickel. The usual formulation is 60% copper, 20% nickel and 20% zinc. It is named german silver due to its silvery appearance, but it does not contain silver.
Q.25. Which of the following is correct combination of masses of the three sub-atomic particles?
[A] Electron – 0. 00055 amu; Proton – 1.0078 amu; Neutron – 1.0083 amu
[B] Electron – 0. 00055 amu; Proton – 1.0083 amu; Neutron – 1.0078 amu
[C] Electron – 0. 00055 amu; Proton – 1.0078 amu; Neutron – 1.0078 amu
[D] Electron – 0. 00055 amu; Proton – 1.0083 amu; Neutron – 1.0083 amu
Answer: A [Electron – 0. 00055 amu; Proton – 1.0078 amu; Neutron – 1.0083 amu]
Notes:
The correct mass of Electron is 0. 00055 amu; Proton is 1.0078 amu and Neutron is 1.0083 amu. Kindly note mass of neutron is slightly more than that of Proton.