Question

Arrange the following. (4)1. Elements of group 1 ( in increasing order of reactivity)2. Elements of group 17 ( in decreasing order of reactivity)3. He, Na, Mg ( increasing of m. pt)4. Cl, Na, Mg ( increasing reducing character)(b) Define following (3)1. Henry`s Law2. Crystallization3. Seeding(c) Give example of each of the following (3)1. Photochemical reaction2. Electrochemical reactions​

Answer 1

Answer:

The increasing order of reactivity among group 1 elements is Li < Na < K < Rb is F > CI > Br > I.

Elements of group 17, in decreasing order of reactivity are F > Cl > Br > I.

He < Na < Mg

Cl < Mg < Na

Henry's law is one of the gas laws states that: at a constant temperature, the amount of a given gas that dissolves in a given type and volume of liquid is directly proportional to the partial pressure of that gas in equilibrium with that liquid.

An everyday example of Henry's law is given by carbonated soft drinks. Before the bottle or can is opened, the gas above the drink is almost pure carbon dioxide at a pressure slightly higher than atmospheric pressure. The drink itself contains dissolved carbon dioxide.

Crystallization or crystallisation is the (natural or artificial) process by which a solid forms, where the atoms or molecules are highly organized into a structure known as a crystal.

Ice and snowflakes are great examples of the crystallization of water.

Seeding is a process in which a small quantity of material (crystal) is used to grow a large quantity of the same material (crystal). Basically it induces crystallization or precipitation. When the leached solution hydrated Al2O3 is obtained, it is seeded with freshly prepared samples of hydrated Al2O3.

Examples of photochemical reactions

Photosynthesis: plants use solar energy to convert carbon dioxide and water into glucose and oxygen. Human formation of vitamin D by exposure to sunlight. Bioluminescence: e.g. In fireflies, an enzyme in the abdomen catalyzes a reaction that produced light.

Galvanic cells are a great example of an electrochemical process. The galvanic cell has the capability of deriving electrical energy from spontaneous REDOX reactions that take place within the cell. The cell consists of two different metals connected together by a salt bridge.