The base has a bitter taste and a slippery texture. A base dissolved in water is called an alkali. When chemically reacting with acids, such compounds produce salts. Bases are known to turn blue on red litmus paper.
When a base reacts with a metal, hydrogen gas is produced. It burns with a pop sound when a burning candle is brought near the test tube’s mouth.
Metal + Base → Hydrogen + Salt
Reaction of base with metals examples
- Sodium hydroxide, as it reacts with zinc metal, gives hydrogen gas & sodium zincate.
2 NaOH + Zn → H2 + Na2ZnO2
- Sodium aluminate and hydrogen gas are formed when sodium hydroxide reacts with aluminium metal.
2NaOH + 2Al + 2H2O → 2NaAlO2 + 2H2
- Sodium hydroxide gives hydrogen gas and sodium zincate when it reacts with zinc metal.
2NaOH + Zn → Na2ZnO2+ H2