Chemistry

Fire extinguisher
The reaction between sulphuric acid and sodium carbonate or sodium hydrogencarbonate is utilized in the making of fire extinguisher as shown in Figure. A sealed glass bottle filled with dilute sulphuric acid is kept inside a container filled with an aqueous solution of sodium carbonate. In case of fire, the plunger is struck against a hard surface to break the bottle. As a result, sulphuric acid comes in contact with the sodium carbonate. The carbon dioxide CO₂ gas which comes out is directed towards the fire.

Acids react with the oxides of metals to form salts and water.

All acids contain hydrogen :
All acids have similar chemical properties. This indicates that all acids must have something in common. You know, all acids react with metal to produce hydrogen gas. Thus, hydrogen is the common substance present in all acids. But all compounds containing hydrogen are not acids. For example, hydrochloric acid and sulphuric acid contain hydrogen and these are acids. On the other hand, alcohol and glucose also contain hydrogen but they are not acids.
The acidic properties of acids are due to the fact that they produce H⁺ ions in aqueous solution.