Why does sodium plus H[sub]2[/sub]O just fizz but sodium plus H[sub]2[/sub]O and CaCl[sub]2[/sub] do more than just fizz ??
Sodium is a chemically reactive metal and easily gives an electron from it’s external layer. The reason why reaction of sodium and water is accompanied by fizzing is that during this reaction sodium hydroxide and gas hydrogen are emitting. This process is represented in equation of the reaction below: 2Na+ 2H2O = 2NaOH +H2 ↑ In reaction with sodium,water, and calcium chloride the situation is the same but after sodium and water reaction there is a further reaction of sodium hydroxide with calcium chloride, which is accompanied by sediment formation. Sediment is calcium hydroxide. This process is represented in equations of the reactions below: 2Na+ 2H2O = 2NaOH +H2 ↑ 2NaOH+ CaCl2 = 2NaCl + Ca(OH)2 ↓