Tag: metals

Metallic substance exists as cations with delocalized electrons.
The positive ions (cations) are arranged to form a kernel in the sea of delocalised electrons. The force of attraction between the positive ions (cations)  and  the sea of delocalised electrons is called the metallic bond.

Carbon reacts with water to form water gas
$ C + H _2O \rightarrow CO + H _2$ 

$ 2K + 2H _2O \rightarrow 2KOH + H _2$

Reaction of 'Na' with cold water. 

Hardness of water due to bicarbonate ion is temporary and can be removed by boiling or through precipitation with calcium hydroxide.

By adding Na$ _{2} $Co$ _{3} $, all the Ca$ ^{+2} $ and and Mg$ ^{+2} $ ions which causes permanent hardness are replaced by Na$ ^{+} $, which doesn't cause hardness.

Permanent hardness of water is due to sulphate ion and chloride ion and cannot be easily removed. It can be removed by treating with washing soda.

Spring water, well water, and river water all are natural water.

Sodium with cold water produces $\displaystyle NaOH, : H _2$
$\displaystyle 2Na + 2H _2O \rightarrow 2Na^+  + 2 OH^- + H _2 \uparrow $

Sodium hydroxide in water gives colorless solution.
Sodium hydroxide is colourless. In water, it dissociates into sodium ions and chloride ions. These ions are also colourless.
$\displaystyle NaOH (aq)   \xrightarrow{H _2O} Na^+ (aq) + OH^- (aq)$