Explanation

• Carbon dating is used to estimate the age of fossils.
• Those that are less than 60,000 years old.
• It is composed of organic materials like wood or leather.

Explanation

In decolorization, particularly in purifying substances like sugar or organic compounds, animal charcoal (also known as bone char) is often used for its adsorptive properties.

The boiling of animal charcoal with hot water serves several purposes:

• Activation
• Removal of Soluble Impurities
• Enhancing Adsorption

The general steps involved in the decolorization process with animal charcoal include:

• Preparation
  
• Mixing
• Adsorption
• Filtration
• Recovery

Explanation

• Ozone (O3) in the stratosphere absorbs ultraviolet radiation from the Sun.
• It preventing excessive heat from reaching the Earth's surface.

Explanation

• A thermometer is typically made up of a glass tube filled with Mercury (Hg), a silvery-white liquid metal.
• The Mercury expands or contracts in response to changes in temperature, allowing us to measure the temperature.

Explanation

All of these compounds are alcohols, but the shorter the carbon chain, the more soluble they are in water.

Ethanol (C2H5OH) has the shortest carbon chain among the options, making it the most capable of forming hydrogen bonds with water molecules, thus leading to higher solubility. 

Explanation

Tollen's reagent detects aldehydes, which reduce Ag⁺ to metallic silver (silver mirror test).

CH₃CHO is an aldehyde, so it reacts with Tollen’s reagent; the others are ketones or acids, which do not.

Explanation

• Ascorbic acid, also known as Vitamin C, is found in various fruits and vegetables.
• But Alma (Emblica officinalis) and citrus fruits like oranges, lemons, and grapefruits are particularly rich in it.

Explanation

The term "phosphatidylcholine" is sometimes used interchangeably with "lecithin," although the two are different.

Choline is a component of phosphatidylcholine, which is a component of lecithin.

Explanation

In 1935, the Tobacco mosaic virus (TMV) was crystallized by Wendell Meredith Stanley.

Stanley's work on TMV contributed significantly to the understanding of viruses

He earned him the Nobel Prize in Chemistry in 1946

Explanation

Basic lead chromate is formed when lead chromate (PbCrO4) is boiled with dilute alkali hydroxide.

Here's the reaction:

PbCrO4 +OH- → PbO⋅PbCrO4 +H2O

In this process, the lead chromate reacts with the dilute alkali hydroxide to form basic lead chromate.

The alkali hydroxide used is typically a dilute solution of sodium hydroxide (NaOH) or potassium hydroxide (KOH).