E-classroom notes of chemistry

 Laws of chemical combination- Law of conservation of mass....      In all physical and chemical changes,the total mass of the reactants in equal to that of the products. Or, Mass can neither be created nor destroyed. This is also called as the law of indestructibility of matter. The mass and energy are intercountable but the total sum of the mass and energy during any physical or chemical changes the names constant. 2Na +Cl2 = 2NaCl Law of constant composition or  definite proportions.... This law was discovered by a French chemist J.L Proust . It's state that, A chemical compound is always found to be made up the same elements combined together in same fixed proportion by mass. Example- A pure water obtained from whatever source or any country will always be made up of only hydrogen and oxygen elements combined together in the same fixed ratio of 1:8 by mass.  A sample of carbon dioxide maybe prepared in the laboratory. a.heating limestone b.by burning coal in air c.by the action

Some basic concepts of chemistry- What is chemistry? ~chemistry deals with the composition structer and properties of matter. These aspects can be best described and understood interm of basic constitution of matter.  Classification of matter- The things which occupy space and having mass which can be felt by our five senses is called matter. Matter is further classified into two types of, 1.physical classification 2.chemical classification Physical classification- It's based on physical State under ordinary conditions of temperature and pressure,so on the basic of two nature of forces,matter can be classified into the following three ways. 1.solid state 2.liquid state 3.gaseos state Solid state- A substance is said to be solid if it prosesses a definite volume and a definite shape  Example- sugar,iron,gold,silver Liquid state-A substance is said to be liquid if it prosesses a definite volume but not definite shape .They take the shape of vessel in which they are put. Example- wate