Question

when hydrogen burns in oxygen what is formed when electricity is passed through water hydrogen and oxygen and give out name the type of chemical change involved in two cases​

Answer 1

Hydrogen is a special element which shows properties of both metal and non-metal.

Whenever Hydrogen burns in free air it vigorously act with the atmospheric oxygen to form an ionic compound. Here, the hydrogen donates electron to the oxygen and hence act as metal having valency +1 while oxygen recieves electrons having valency - 2.

Hence, the ionic compound form by the two substance is Dihydrogen-Oxide which is nothing except water.

This is a combination reaction as two substance combine with each other to form a new- single substance.

${H}_{2}(g) + {O}_{2} (g) \rightarrow {H}_{2}O (l) \\ \\ {H}_{2}O (l) \rightarrow {H}_{2}(g) + {O}_{2} (g)$

In the second equation the water is again converted into hydrogen and oxygen by means of electrolysis . This is an example of decomposition reaction as a single substance get splited into two products (just reverse of combination reaction ).

Answer 2

Hydrogen is a special element which shows properties of both metal and non-metal.

Whenever Hydrogen burns in free air it vigorously act with the atmospheric oxygen to form an ionic compound. Here, the hydrogen donates electron to the oxygen and hence act as metal having valency +1 while oxygen recieves electrons having valency - 2.

Hence, the ionic compound form by the two substance is Dihydrogen-Oxide which is nothing except water.

This is a combination reaction as two substance combine with each other to form a new- single substance.