Question

With the help of balanced chemical equation explain what happens when:(1)Zinc is put in dilute hydrochloric acid (2)Zinc is put in concentrated sodium hydroxide.(3)Hydrogen is passed over hot tungsten oxide.(40Hydrogen is reacted with carbon monoxide in presence of a catalyst.

Answer 1

Answer:

1) $Zn(s)+2HCl(aq)--->ZnCl_{2}+H_{2}(g)$

2) $Zn+2H_{2}O+2NaO-->Na_{2}Zn(OH)_{4}+H_{2}(g)$

3) $3H_{2}(g)+W_{2}O_{3}--->3H_{2}O+2W(s)$

4) $CO(g)+2H_{2}(g)--->CH_{3}OH$

Explanation:

The following happens:

(1)Zinc is put in dilute hydrochloric acid

There is an evolution of hydrogen gas as the Zinc undergoes oxidation by hydrogen and it reduces the hydrogen to hydrogen gas.

$Zn(s)+2HCl(aq)--->ZnCl_{2}+H_{2}(g)$

(2)Zinc is put in concentrated sodium hydroxide.

Again there is evolution of hydrogen gas and formation of zincate sodium. This happens when we heat the mixture.

$Zn+2H_{2}O+2NaO-->Na_{2}Zn(OH)_{4}+H_{2}(g)$

(3)Hydrogen is passed over hot tungsten oxide.

The hydrogen reduces the tungsten metal during the reaction and it gives solid tungsten metal.

$3H_{2}(g)+W_{2}O_{3}--->3H_{2}O+2W(s)$

(4) Hydrogen is reacted with carbon monoxide in presence of a catalyst.

This is producer gas reaction.

$CO(g)+2H_{2}(g)--->CH_{3}OH$