Notes, Exercises, Videos, Tests and Things to Remember on Bases
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Oxides of metals are called base. They are soapy to touch.
Those compounds which release hydroxyl ion (Anion) in their aqueous solution are called base.
NaOH→Na+ + OH-
Ca(OH)2→ Ca+++ 2OH-
Mg(OH)2 → Mg++ + 2OH-
Alkali: Some metallic oxides (base) give their respective hydroxide when dissolved in water. Such water-soluble bases are called alkalis.
On the basis of strength, bases are of two types:
Similarly, on the basis of their origin, bases are of two types:
Fig: Formation of hard water
A base is a substance which gives hydroxyl ion (OH-) when dissolved in water.
Usually all bases or the oxide of metals are soluble in water but some bases like CuO, Fe2O3, etc. are not soluble in water. The bases which are soluble in water are called alkali. As all bases are not soluble in water, all alkalis are bases but all bases are not alkali.
The names of two antacids are as follows: a. Sodium hydrogen carbonate b. Mixture of aluminum hydroxides and magnesium hydroxides.
Calamine lotion or sodium hydrogen carbonate is used for the treatment for a nettle sting or ant-bite.
Copper sulphate is prepared by the reaction between an insoluble base and acid. At first, some copper oxide is added to dilute sulphuric acid. On warning, it dissolves and the solution turns blue. More copper oxide is added until no more dissolve. The excess of solid is removed by filtering. This leaves a blue solution of copper sulphate. The solution is heated to evaporate some of the water content. Then it is left to cool. Blue crystals of copper sulphate start to form.
When H2SO4 is dissolved in water, it gives (H+). Therefore, it is called acid. When NaOH is dissolved in water, it gives hydroxides ions (OH-). Therefore, this is called base.
Acetic acid gives less number of hydrogen ion (H+) in water. Therefore, it is called weak acid. When ammonia solution is ionized it gives less number of hydroxyl ion (OH-). Therefore, it is called weak alkali.
Oxide of metals are called ______.
If _______ ions are found in a solution, the solution is basic in nature.
hydrogen and oxygen
The reaction of an acid with a base is called a ______.