Explanation

Lactose, also known as milk sugar.

It is a disaccharide composed of galactose and glucose molecules.

It is found in milk and other dairy products.

Explanation

In qualitative analysis, a sample can be a solid, liquid, gas, or a mixture.

A mixture is a physical combination of two or more substances, where each substance retains its chemical properties.

Explanation

Amino acids are the building blocks of proteins, which are long chains of amino acids linked together by peptide bonds.

There are 20 different amino acids that the human body uses to build proteins.

They are essential for various cellular processes, including structure, function, and regulation.

Explanation

Glucose (C6H12O6) is a type of carbohydrate, specifically a simple sugar or monosaccharide.

It is a vital source of energy for many living organisms, including humans.

Glucose is a primary component of many carbohydrates, such as starch, cellulose, and glycogen.

Explanation

Sodium carbonate is also known as washing soda.

It is commonly used to remove permanent hardness from water.

It reacts with calcium and magnesium ions, which are the causes of permanent hardness, to form precipitates that can be removed from the water.

Explanation

The bottom of the stratosphere is around 10 km (6.2 miles or about 33,000 feet) above the ground at middle latitudes.

The top of the stratosphere occurs at an altitude of 50 km (31 miles).

Explanation

Amphoteric substances are those that can react with both acids and bases.

They can donate or accept protons (H+ ions), depending on the conditions.

Examples of amphoteric substances include water (H2O), amino acids, and certain metals like zinc and aluminum.

Explanation

Kerosene oil is used as jet fuel, commonly known as Jet-A or Jet-A1.

It has a high energy density and good combustion properties suitable for aircraft engines.

Explanation

The carboxylate end of a soap molecule (-COO-) is hydrophilic (water-loving), meaning it is attracted to water.

This end of the molecule is negatively charged and is able to form hydrogen bonds with water molecules, which are polar and also have a slightly positive charge.

Explanation

Ammonia (NH3) is not a fraction of crude oil.

Crude oil is a mixture of various hydrocarbons, which are separated into different fractions based on their boiling points and properties.

The main fractions of crude oil are:

• Refinery gas
• Liquefied petroleum gas (LPG)
• Naphtha
• Gasoline
• Kerosene
• Diesel fuel
• Fuel oil
• Lubricating oils
• Paraffin wax
• Petroleum coke (also known as petcoke)