Our aim in this article is to help students prepare students for SSC chemistry. Students need to polish their skills in chemistry lessons for all their upcoming relevant examinations at the senior secondary level. We will not only discuss some relevant topics but will also talk about the importance and scopes of chemistry. It is important to impress upon the students the necessity to study each topic diligently, be it molecular structure, chemical structure, atomic theory, acids and bases, the periodic table, chemical reactions, organic or inorganic chemistry, redox reaction or about hydrogen or hydrocarbons.
Knowledge about general chemistry will surely fetch you pass marks but in today’s competition, it would mean nothing. If you have to leave a mark in the field of chemistry or even aspire to get yourself enrolled in an esteemed college or university, you must be ready to go an extra mile or more to secure your dreams. With the hectic rat race, it has become very difficult for the average student to even land a job. So subsequently he/she has to compromise with career and apply for jobs which are either very low paying or temporary.
Do not waste this phase of your life for futile fun and frolic. This is the most decisive fragment of a student’s life which will determine not just your placement in a college but the standard of living you will be able to afford and your prestige in the society. With making you aware of the importance of studying chemistry, we shall now proceed to discuss very important topics that form a part of your syllabus. Whatever board you may belong to, these following topics are an integral part of any curriculum. They form the basis of the subject and thus, should be studied without any ifs and buts at this level.
Matter And Its Properties
What Is Matter?
Before undertaking the course of explaining the properties of matter, it is necessary for us to know about matter itself. In physics and chemistry, anything that has mass and volume is called matter. Mass is the total substance in a matter and volume is the measure of space that is acquired by the matter.
Every tangible thing around us is matter. Everything is made up of atoms. Each atom consists of neutrons and protons. A molecule is further a group of atoms. There are three states of matter, solid, liquid and gas.
Properties Of Matter
We are familiar with matter since we are always surrounded by it. Anything that takes up space can be called ‘matter’. Right from the pen you use for writing to a wooden chair, everything around us is matter. Every matter can be measured in one way or another which will establish its properties. This determination of the characteristic or behaviour of a matter is called its property. For example, water can be boiled at 100-degree Celsius, this gives us its characteristics and thus makes up a property.
There are several properties of matter such as its density, colour, mass, volume, hardness, malleability, melting point, mass length, temperature etc. We shall elaborate on a few of these varieties of properties.
- The physical properties of a matter include its shape, size, texture etc. the melting and freezing points also come under physical properties. The physical property of a certain substance is what differentiates it from another substance. For example, why is glass not similar to wood? Because they have contrastive physical properties.
- The chemical properties, on the other hand, are the chemical composition of a substance and how they react in relation to other chemical substances. During a chemical reaction, a new substance is often formed. This happens when two chemicals of two respective substances collide and react. For example, mixing an acid (HCl) with a base (NaOH).
Mass is the most important property of any substance. It is the amount of matter that the substance contains. It does not change with location and is directly related to inertia. For example, a man on the moon will weigh less but will have the same amount of mass as he has on the earth.
Density is often called volumetric mass density. It is a substances’ mass per unit volume. Its mathematical formula is mass divided by volume. Density is not constant under every circumstance but differs with temperature and pressure. The difference is almost negligible for solid and liquid substances but much higher in gases. Density also determines floatation. For instance, wood floats in water because the former has a lesser density.
Reactivity is the property of a chemical substance which gives it an impetus to a chemical reaction. It can be a reaction of one or more than one substance. It can also give rise to a completely new substance.
Flammability is the property of matter which makes it burn. When matter burns, it comes in contact with oxygen and is transformed completely.
Why Is It Important For Us To Know The Properties Of Matter
It is important for us to know about the properties of matter because they form an integral part of the syllabus. Clear knowledge about this will definitely be of help in experiments conducted in the chemistry lab which often include chemical bonding like oxidation-reduction including substances like alkane, ideal gas, catalysts or other chemical compounds. It will immensely help you gather a crystal clear perception of organic chemistry courses. The same can also be said about inorganic chemistry.
Bonding or chemical bonding is one of the indispensable chemistry topics that we come across at the SSC level. This chapter is often considered too difficult because, on the surface, it looks like an impossible feat to overcome. But fortunately, it is not so.
A chemical bond is an attraction between atoms, molecules or ions. This attraction enables the formation of chemical compounds. The bond may be caused due to the attraction between ions which are oppositely charged or by the sharing of electrons which we call covalent bonds. Chemical bonds can be further divided into strong bonds and weak bonds-
- Strong bonds are also called primary bonds. This category includes covalent, metallic and ionic bonds.
- Weak bonds are also called secondary bonds which include dipole-dipole interactions, hydrogen bonding and the London dispersion.
A covalent bond is a chemical bond that is caused by the sharing of electron pairs between atoms. The bonding pairs are the electron pairs. While the balance of opposite forces between atoms is known as covalent bonding. This covalent bonding takes place when they are sharing electrons. Covalent bonding may include several kinds of interaction like metal-to-metal bonding, bent bonds, three-centre two-electron bonds, agostic interactions etc. The hydrogen (h2) is made up of atoms sharing 2 electrons through covalent bonding.
Structures Of Covalent Bonds
Covalent substances have several types of structures. They include molecular structures, macromolecular structures, individual molecules, and giant covalent structures.
Molecular structures often have a weak force of attraction. This type of structure includes substances like ethanol which are low-boiling-temperature liquids or low-melting-solids like the solid carbon dioxide.
Macromolecular structures are such which have a large number of atoms making up a covalent bond. They are all linked together. The synthetic polymers and biopolymers fall under this structure. For example, nylon, starch, polyethene, etc.
Individual Molecules Structure
Individual molecules have the strongest bonds which hold the instability of the atom. But there is hardly any attraction between the molecules. Gases have such covalent structures. For example, co2, so2, HCl etc.
Giant Covalent Structures
A giant covalent structure is one which holds together the atoms in a three-dimensional fashion. Quartz and diamond would serve as an example of this structure. They are also called network covalent structures. They contain many atoms sometimes linked in sheets like the graphite. These substances are often brittle and have high boiling and melting points. They are high in electrical resistivity, which means it strongly resists the conduction of electricity.
Hopefully, chemical bonding is now less intimidating. To polish your skills further, delve deep into your own chemistry research by reading and writing more about it. Besides bonding, students must engage in deeper and more systematic preparation of SSC examination. Your academic exercises must not be limited to that of the school alone. Try to solve past papers and test questions of chemistry. You can also take part in the Olympiad competition that takes place all over the country. This competition posits multiple-choice questions to you and your performance will facilitate you to actuate where you stand in your preparations.
Remember no topic in the SSC chemistry syllabus is unimportant. You cannot afford to skip any chapter. Chemistry is a very conceptual subject and exempting any one topic could prove to be a calamitous decision which in turn would affect your entire life. If at the SSC level your foundation falters, there is no way you can pull yourself up. Thus studying arduously for your SSC examination is the safest bet. It will not only secure your position in the report card of your 12th standard but also in the world out there.