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Chapter 8

Water

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The following Topics and Sub-Topics are covered in this chapter and are available on MSVgo:

Introduction

Water is a colourless, translucent organic material that makes up most of the earth’s ponds, seas, and lakes. It is crucial for the existence of life on earth. H2O is the molecular formula for water. It is formed by covalent bonds that hold two hydrogen atoms and one oxygen atom together. This liquid takes up 71 percent of the earth’s surface.

Since it can dissolve more liquids than any other material, water is regarded as the “universal solvent.” Water is important for all living beings. It transports essential chemicals, minerals, and nutrients when it moves through the air, the sea, or our bodies. 

The chemical structure and physical properties of water make it a good solvent. The oxygen and hydrogen atoms in water molecules are structured in a polar configuration, with one side (hydrogen) providing a positive electrical charge and the other side (oxygen), a negative charge. This enables the water molecule to attract a wide range of other molecules.

A suspension is a heterogeneous fluid in which rigid particles are distributed in the liquid but do not dissolve. A suspension is a homogeneous mixture of particles with a diameter larger than 1000 nm and apparent to the naked eye. Many of the elements perfectly combine with this kind of combination, and the particles can be seen under a microscope. A suspension is a heterogeneous mixture comprising solid particles large enough to enable sedimentation.

Colloids are described as a mixture in which one of the substances is broken down into tiny particles scattered in a second material. Colloidal particles are the tiniest particles. On the other hand, colloids are simple solutions of solute particle sizes varying from 1nm to 1000nm. They are naturally heterogeneous.

A set number of molecules in one formula of a unit of salt is referred to as crystallization water. Hydrates are crystal salts that absorb water during the crystallization process. Water crystallization is also known as crystallization water or hydration water. The formation of purified crystals from an aqueous solution causes the water to crystallize. Contaminants are not present in these crystals. The heat has a strong effect on these crystals.

Hydrous compounds are chemical compounds that include water molecules as a constituent of their form. Organic substances with no water molecules in their form are known as anhydrous compounds. This is the key distinction between hydrous and anhydrous substances. Hydrates are a type of hydrous compound. Anhydrates are a type of anhydrous compound. 

The word “hydrous” refers to a material where water is a constituent. The water here applies to the crystallization water. Since these compounds cannot crystallize without water, water may be trapped within the crystal lattice of substances during crystallization. 

The word “anhydrous” refers to a material that does not produce water as a constituent. It refers to a compound devoid of liquids. They are called anhydrous compounds. Different methods may be used to extract anhydrous compounds. Based on the form of substance, the extraction methods vary. The colours and chemical properties of certain anhydrous substances differ from those of their hydrous counterparts.

The disadvantages of using hard water are:

  • Disposal of soap 
  • Fuel wastage 
  • Scale formation on metallic boilers

When salt is combined with water, it dissolves since the water’s covalent bonds are stronger than the salt molecules’ ionic bonds.

Salt dissolves in water at the molecular level due to electrical charges. All water and salt substances are polar molecules with positive and negative charges on opposite sides. The ionic bonds of salt compounds are so named because both the chloride and sodium ions have an electrical charge—the chloride ion is negatively charged, whereas the sodium ion is positively charged. A water molecule is also ionic, but the bond is considered covalent since two hydrogen atoms exist with their positive charges on one side of the oxygen atom, which negatively charges. 

The negatively charged chloride ions attract the positively charged water molecules, while the positively charged sodium ions attract the negatively charged water molecules. The ionic bond that held the sodium and chloride ions are broken as water molecules force them apart. The sodium and chloride atoms are surrounded by water molecules after the salt compounds separate. The salt dissolves at this stage, resulting in a homogeneous solution.

In this chapter, we learned about water and its properties. We can use this knowledge to differentiate between unsaturated, saturated, and supersaturated compounds.

  1. What makes a water molecule?
  2. A water molecule comprises three atoms: an oxygen atom and two hydrogen atoms magnetized together. Atoms are made up of matter with a nucleus in the centre.
  3. What is the mass of a water molecule?
  4. A molecule’s weight is measured by the atomic masses of the atoms forming it. This translates to a mass of 18 g/mol.
  5. In what states (phases) does water exist?
  6. There are three phases of water: solid, liquid, and gaseous.
  7. What is the definition of hard water?
  8. Hard water has more minerals than normal water.
  9. What are the differences in physical and chemical properties?
  10. Physical characteristics of a material refer to the appearance of the substance. Chemical properties are properties commonly used in chemistry to characterize a substance’s state.

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