Chemistry Basics

Explanation

Water can dissolve more substances than any other liquid because of its dipolar nature. Water molecules have a partial positive charge on the hydrogen atoms and a partial negative charge on the oxygen atom, making it a polar molecule. This polarity allows water to form hydrogen bonds with other polar or charged substances, facilitating the dissolution of a wide range of solutes.

Explanation

In the given pairs, the sources are correctly matched for Carmine, which is obtained from the Cochineal insect, and Shellac, which comes from the Lac insect. However, the sources for Asafoetida and Lapis lazuli are incorrectly matched. Asafoetida is derived from plant resin, not lichen. Therefore, the correct answer is option (b) 2 and 4 only.

Explanation

In a dry cell (battery), the electrolytes used can be either ammonium chloride or zinc chloride, with the latter being a common replacement in modern batteries.

Explanation

In the context of ionic compounds, the statements provided are as follows: 1. Ionic compounds do not dissolve in alcohol. 2. Solid ionic compounds do not conduct electricity. The correct answer is option (d), which means that neither of the statements is accurate.

Explanation

Liquid sodium is utilized as a coolant in fast breeder nuclear reactors because of its effective heat transfer abilities.

Explanation

The Aufbau principle explains that electrons occupy orbitals based on their energy levels in an increasing order.

Explanation

Zirconium is the only non-radioactive element among the options provided. Astatine, Francium, and Tritium are all radioactive elements.

Explanation

In large cold storage plants, ammonia is used as a refrigerant, while chlorofluorocarbons are used in domestic refrigerators. The assertion that ammonia can be liquefied at ambient temperature and low pressure is false as it actually requires high pressure to liquefy at ambient temperature.

Explanation

In this chemistry question, you were asked to match items in List-I with their corresponding elements in List-II. German silver is composed of nickel, solder contains tin, bleaching powder includes chlorine, and hypo consists of sodium. The correct matching is German silver with nickel, solder with tin, bleaching powder with chlorine, and hypo with sodium. So, the correct option is (d) A-2; B-1; C-4; D-3.

Explanation

Anodizing is a process that forms a protective layer of aluminium oxide on aluminium surfaces.

Explanation

In the given statements, it is stated that hard water is not suitable for drinking, washing clothes with soap, use in boilers, and irrigating crops. The correct option is (b), which means statements 2 and 3 are correct. Hard water affects the effectiveness of soap and leads to scale build-up in boilers. It is not recommended for washing clothes with soap or for use in boilers, but it is suitable for drinking and irrigation.

Explanation

When diluting sulphuric acid, it is important to add acid to water slowly to avoid a sudden and potentially dangerous reaction. The specific heat of water, which is relatively high, is not the primary factor influencing this process.

Explanation

In this question, you were asked to match naturally occurring substances with the elements they contain. Diamond contains carbon, marble contains calcium, sand contains silicon, and ruby contains aluminium. The correct match is: A-4; B-1; C-2; D-3.

Explanation

In this question, you had to match the substances in List I with their corresponding names in List II. Blue vitriol refers to copper sulphate, Epsom salt is magnesium sulphate, Baking soda is sodium bicarbonate, and Caustic soda is sodium hydroxide. The correct matching is A-4; B-3; C-1; D-2, as given in option (d).

Explanation

In the field of chemistry, different potassium compounds are used in various industries. Potassium bromide is utilized in photography, potassium nitrate is found in gunpowder, potassium sulphate acts as a fertilizer, and monopotassium tartarate is a key ingredient in bakery products. Matching these compounds with their respective industries, we find that A-2; B-4; C-1; D-3 is the correct combination.

Explanation

In the process of producing steel/iron in a blast furnace, coke is a material added to the charge. It serves the functions of acting as a reducing agent and providing fuel for heat generation. This helps in reducing the iron ore and facilitating the production process.

Explanation

Iron does not react with mercury to form an amalgam, unlike zinc, copper, and magnesium which can form these alloys.

Explanation

Sodium metal is stored under kerosene to prevent its reaction with air and moisture. This is necessary because sodium is highly reactive and can easily react with the oxygen and water vapor in the air. It is not stored under kerosene because it melts when exposed to air.

Explanation

Fluorine is the most reactive halogen because of its small size and high electronegativity, making it the top choice among the halogens.

Explanation

The alpha particle contains two protons and two neutrons, giving it a mass that is very close to that of a helium atom.

Explanation

Stainless steel is a type of alloy that is made up of iron, chromium, and nickel. This combination gives it the property of being resistant to corrosion.

Explanation

Nickel and cadmium are the materials that serve as electrodes in rechargeable batteries commonly found in devices like torchlights and electric shavers. These batteries, known as nickel-cadmium (NiCd) batteries, are frequently used in portable gadgets.

Explanation

NPK fertilizer is a type of mixed fertilizer that includes nitrogen, phosphorus, and potassium, which are all vital nutrients for plants.

Explanation

Sodium thiosulphate is the chemical used as a 'fixer' in photography because it eliminates unexposed silver bromide from photographic film.