Practice MCQ Questions and answers on Chemistry-GK

An electrical fuse is a safety device in the circuit that protects electrical systems by breaking the connection when a short circuit is occurring. The fuse wire is made up of Sn (tin) and Pb (lead) alloy because of its high resistance and low melting.

Sulphonate is a detergent used for cleaning clothes and utensils.

Ethephon helps in fruit ripening.

Silver halide is the most important chemical used in photographic processing. It is the key component of the emulsion.

Artificial rainmaking, also known as cloud seeding, is a way to increase rainfall.
It involves sprinkling certain chemicals into clouds to encourage them to release their water.
Silver iodide (AgI) is a very common chemical used for this purpose. It works because its crystal structure is similar to ice, attracting water molecules and helping form larger raindrops.
Sodium chloride (NaCl), or common table salt, can also be used, though less frequently than silver iodide. It also helps in the formation of rain droplets.
Dry ice (frozen carbon dioxide, CO2) is another substance used in cloud seeding. It cools the air around it, creating ice crystals that help to make rain.
Therefore, all three options - silver iodide, sodium chloride, and dry ice - are used in artificial rainmaking.
The correct answer is D: All of the above.

Malathion is an insecticide in the chemical family known as organophosphates. Products containing malathion are used outdoors to control a wide variety of insects in agricultural settings and around people's homes. Malathion has also been used in public health mosquito control and fruit fly eradication programs.

Zinc phosphide is used as a rodenticide. A mixture of food and zinc phosphide is left where the rodents can eat it. The acid in the digestive system of the rodent reacts with the phosphide to generate the toxic phosphine gas.

Chromium is mainly found in waste from the chrome tanning process; it occurs as part of the retanning system and is displaced from leathers during retanning and dyeing processes. This chrome is discharged from processes in soluble form; however, when mixed with tannery waste waters from other processes (especially if proteins are present), the reaction is very rapid. Precipitates are formed, mainly protein-chrome, which add to sludge generation. If chrome discharges are excessive, the chromium might remain in the solution. Even in low concentrations, it has a toxic effect upon daphnia, thus disrupting the food chain for fish life and possibly inhibiting photosynthesis.

The active ingredient in Dettol that confers its antiseptic property is chloroxylenol (C₈H₉ClO), an aromatic chemical compound. Chloroxylenol comprises 4.8% of Dettol’s total mixture, with the rest composed of pine oil, isopropanol, castor oil soap, caramel and water.