Option “C” is correct Sewage sludge refers to the residual, semi-solid material that is produced as a by-product during sewage treatment of industrial or municipal wastewater.
Option “A” is correct Every type of particle has a corresponding antiparticle, for example; the positron is the antiparticle of the electron. the antiproton is the antiparticle of the proton. the antineutron is the antiparticle of the neutron. the antineutrino is the antiparticle of the neutrino.
73. Which of the following is used as non-stick coating for cooking utensils?
1. Perspex
2. Styrofoam
3. Polystyrene
4. Teflon
Option “D” is correct Non-stick cookware is a common application, where the non-stick coating allows food to brown without sticking to the pan. Non-stick is often used to refer to surfaces coated with “Teflon.”
74. The purest form of iron is –
1. Cast iron
2. Steel
3. Pig iron
4. Wrought iron
Option “D” is correct Wrought iron contains 0.12 to 0.25% carbon and it is the purest form of iron.
75. The atoms, in which the number of protons is same but the number of neutrons is different, are known as-
1. Isobars
2. Isomers
3. Isotones
4. Isotopes
Option “D” is correct The Isotopes are a set of nuclides/atoms having the same number of protons, but a different number of neutrons. In other words, the same atomic number having different atomic mass.
76. Which of the toxic heavy metals is found in modern tannery industries?
1. Nickel
2. Zinc
3. Chromium
4. Lead
Option “C” is correct Chromium is the toxic heavy metal and mainly found in waste from the chrome tanning process; it occurs as part of the retaining system and is displaced from leathers during retaining and dyeing processes.
77. The main source of carbon monoxide is –
1. Industrial process
2. Agricultural activities
3. Combustion of fossil fuels
4. Solid waste disposal
Option “C” is correct The main source of carbon monoxide is burning of fossil fuel. The combustion of petroleum in automobiles is incomplete due to which smoke is produced. This smoke contains carbon monoxide.
78. Which of the following is used to decolourise Brown Sugar Solution is –
1. Coal
2. Hydrochloric Acid
3. Charcoal
4. None of these
Option “C” is correct A special characteristic of charcoal is power to remove substances from solution. A brown solution of raw sugar is decolouries when boiled with charcoal.
79. The chemical formula of baking soda is:
1. Ca(OH)2
2. NaHCO3
3. CaCO3
4. Na2CO3
Option “B” is correct Sodium bicarbonate is also known as Baking Soda. The chemical formula of Sodium Bicarbonate is NaHCO3.
80. Which one of the following pairs is not correctly matched?
1. Dry ice : Solid carbon dioxide
2. Mustard gas : Poisonous liquid used in chemical warfare
3. Teflon : Polymer containing fluorine
4. Fullerene : Organic compounds containing fluorine
Option “D” is correct Dry Ice – We can simply say that Dry ice is solid Carbon dioxide CO_2. It is used as a cooling agent. Mustard gas – It is used as a strong chemical weapon. This mortally chemical affects skin, leering eye, lungs and D.N.A. which affects the cells most.
Q. 1. Ribosomes are made up of..
1. Protein and RNA
2. Protein and DNA
3. Carbohydrates
4. Cellulose
Q. 2. Electron transport chain occur at …
1. Protein fibre
2. Cellulose
3. mitochondrial inner membrane
4. Callose
banothshailu@123gemil.come
Which instrument is used to capture the purity of milk?
(A) hydrometer
(B). Isometric
(C). Lacto meter
Lactometer
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…
Protein and RNA
Protein and RNA
vvvwvrww
Very good
Question bank chapter wise for class 12th CBSE 2025 board examination PCB