• 3 months ago
Transcript
00:00Solution, when a substance dissolves in a liquid, what we get is called a solution.
00:18To prepare the lemonade, we add sugar, salt and lemon juice to the water.
00:30The prepared lemonade is called a solution, while the substances that were dissolved in
00:40it, sugar, salt and the lemon juice are solutes.
00:51The liquid, that is water in this case, in which the solute dissolves is called a solvent.
01:03The solute is always lesser in quantity than the solvent.
01:14Solubility, solubility is the ability of a substance to dissolve in a liquid.
01:24When a substance completely mixes into a liquid, it is referred to as a soluble substance for
01:32that particular liquid.
01:35Sugar, salt and lemon juice are soluble in water.
01:45Some other soluble substances that dissolve in water are honey, coffee, etc.
01:58When we add substances such as sand, small pebbles, oil or chalk powder into different
02:11glasses filled with water, we find that these substances do not dissolve in water.
02:23Substances that do not dissolve in a liquid are called insoluble substances.
02:31Wood, plastic and sand are insoluble substances since they do not dissolve in water.
02:46Saturated Solution
02:47A soluble substance can dissolve in a solvent only up to a certain extent.
03:01If you keep adding sugar to a glass of water and keep stirring, a stage will come when
03:09the sugar will no more dissolve in it at that temperature.
03:16The extra sugar will settle down at the bottom of the vessel.
03:23Such a solution is called a saturated solution.
03:30In a saturated solution, the solubility of the solute reaches a limit beyond which no
03:38more of it can be dissolved in the solvent.
03:45There is a fixed quantity of a solute that forms a saturated solution for a fixed quantity
03:54of solvent.
03:58The solubility of a substance can be increased in the following ways.
04:051.
04:06A substance dissolves faster if we warm the solvent and stir the solute in it continuously.
04:162.
04:17A powdered form of the solute helps it to dissolve in the solvent faster than the whole
04:26piece.
04:33Some Useful Solvents
04:38We know that water is the most common solvent and is widely used in our daily life.
04:49There are, however, other solvents that we use not just in our homes but also in industries
05:01and factories.
05:06These include kerosene, petrol and turpentine.
05:16Petrol is used at times to remove grease stains on clothes.
05:24When petrol is applied to a grease stained cloth, the grease on the cloth dissolves
05:31in it and thus the cloth becomes stain free.
05:40Kerosene is commercially used as a cleaning solvent for machines to remove grease and
05:47other lubricants.
05:52Kerosene oil is used in oil paintings as a thinner especially to keep paint brushes clean.