Chemistry MCQs

Notes:
Bitumen is a mixture of organic liquids that are highly viscous, black, sticky, soluble in carbon disulfide and composed of highly condensed polycyclic aromatic hydrocarbons.

Notes:
Potassium permanganate is a point-of-entry treatment method that oxidizes dissolved iron, manganese, and hydrogen sulfide into solid particles that are filtered out of the water. It can also be used to control iron bacteria growth in wells.

Notes:
Transuranic elements are those with atomic numbers greater than 92, which is the atomic number of uranium. These elements, including plutonium (94) and americium (95), are all synthetic and typically unstable, often used in nuclear applications and research. The term “transuranic” specifically refers to elements beyond uranium in the periodic table.

Notes:
Ozone (O3) is the most common photochemical oxidant in photochemical smog. Inhaling ozone can cause irritation to the mucous membrane and respiratory system. Ozone can also cause chest constriction and damage to vegetation.

Other components of photochemical smog include:

• Nitrogen dioxide (NO2)
• Peroxyacetylnitrate (PAN)
• Aldehydes

Other air pollutants that can be harmful to humans include:

• Sulfur dioxide
• Volatile organic compounds (VOCs)
• Dioxins
• Polycyclic aromatic hydrocarbons (PAHs)

Carbon monoxide can cause hyperventilation, respiratory distress, and stillbirths. At high levels, carbon monoxide can even cause direct poisoning.

Notes:
Tear gas is also known as CS Gas. It acts as a lachrymatory agent. Tear gas irritate the mucous membrane of the eyes, nose, mouth and lungs, and causes tearing, coughing, burning and difficult breathing.

Notes:
Ammonia is a colourless gas with a pungent odour. Its aqueous solution is weakly basic due to the formation of OH^– ions. The ammonia molecule is trigonal pyramidal in shape.

Notes:
The term pewter covers a variety of alloys consisting primarily of tin. It is composed of 85–99% tin, mixed with copper, antimony, bismuth, silver or lead..

Notes:
Corundum is an ore of Aluminium. It is a crystalline form of aluminium oxide. Kieserite is an ore of Magnesium and Pitch blende is an ore of Uranium.

Notes:
The probability of finding an electron at a point within an atom is proportional to the square of the orbital wave function i.e., ψ|² at that point. |ψ|² is known as probability density and is always positive.

Notes:
The general formula is that the nth shell can hold up to 2n² electrons. For example: for L shell n =2, so maximum number of electrons will be 2(2²) i.e. 8.