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Empirical Formula an be calculated by the following steps. •Assume a definite starting quantity of the compound, if not given and express the mass of each element in grams. •Convert the grams of each element into moles using each elements molar mass. This conversion gives the number of moles of atoms of each element in the quantity assumed in previous step. •Divide each value obtained in previous step by the smallest values. If the numbers obtained are whole numbers, use them as subscripts and write the empirical formula. •Multiply the values obtained in the previous step by the smallest number that will convert them to whole numbers. Use these whole numbers as the subscripts in the empirical formula.

            The technique uses a set of apparatus with which volumes of solutions can be measured to an accuracy of greater than 0.1 cm3. Three important pieces of apparatus are: •Burette - Measures accurately the volume of a solution added. Readings can be taken to an accuracy of half a division. •Pipette - Delivers an accurate volume of a solution. Often this is 25 cm3. •Volumetric flask - Used to make up an accurate g of a solution, for example, 250 cm3. This could be a standard solution (of exactly known concentration and known solute).

Electrolysis of dilute sodium chloride solution Electrolysis of concentrated sodium chloride solution   At anode :                       Anions :  OH-   and   Cl-   OH- ions are selectively discharge according to the position of ions in the Electrochemical Series, ES.   Gas bubbles are formed which lighted up a glowing wooden splinter. This gas is oxygen.   4OH- ---> 2 H2O  +  O2   +  4e   At anode :                       Anions :  OH-   and   Cl-   Cl- ions are discharged instead of OH- because of their higher concentration in the electrolyte.   A greenish-yellow gas with a pungent and choking smell is released. The gas turns the blue litmus paper red and then white.   2Cl-  --->  Cl2    +...

Acidic,Basic and Neutral Substances Acidic substances Materials that contain an acid in them are called acidic substances. Acids are of 2 types- •Mineral Acid •Organic Acid Mineral Acid A mineral acid is an acid derived from on or more inorganic compounds.They are not Organic. Examples are-Sulphuric Acid,Nitric Acid. Organic Acid They occur naturally in animal and plant materials Ex: Tartaric Acid from Grapes,Lactic acid from milk. Characteristics of Acidic Substances are- •They have a sour taste and are corrosive •They are soluble in water Acids can also be either dilute or concentrated. Acids with more amount of water are called dilute acids.Acids with less amount of water are called concentrated acids. Acids can also be either strong or weak. Strong acids are highly corrosive and can cause burns.Ex:Nitric,Sulphuric Acid Weak acids are not so destructive. Basic Substances Substances that contain a base are called basic substances. Examples are Sodium Hy...

Titration Formula A titration can determine the volume of one solution required to react exactly with a known volume of another solution. Titration frequently involve the reaction other than acid-base reactions, such as redox reactions and reactions involving precipitations. "A titration can determine the volume of one solution required to react exactly with a known volume of another solution." The equation for Titration Formula is expressed as Titration Formula Where •N = normality of titrant •V = volume of titrant •Eq.wt = equivalent weight of acid •W = mass of sample •1000 = factor relating mg to grams However in common the Titration Formula is written as Titration Formula Where •N = normality of titrant •V1 = volume of titrant •Eq.wt = equivalent weight of predominant acid •V2 = volume of sample