Question

4. What is observed when hot concentrated caustic soda
solution is added to (a) Zinc and (b) Aluminium ? Write
balanced equations.​

Answer 1

Hey mate...

Here's your answer

a) Zinc react with hot conc. caustic soda or hot conc. sodium hydroxide to produce zincate sodium and hydrogen.

Zn+2NaOH→Na2ZnO2+H2

b) Aluminum react with sodium hydroxide to produce sodium aluminate, hydrogen and sodium oxide.

2Al + 6NaOH ----->2NaAlO2 + 3H2 + 2Na2O

Hope it's helpful for you ^-^

Have a good day

Answer 2

Answer:

a) Zinc reacts with hot conc. caustic soda (NaOH) to produce Sodium zincate  and hydrogen.

Zn +  2NaOH   →   $Na_{2} ZnO_{2}$   +   $H_{2}$

b) Aluminum react with sodium hydroxide to produce Sodium aluminate and hydrogen.

2Al   + 6NaOH  →   $2Na_{3} AlO_{3}$   + $3H_{2}$

Hope it helps

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