Question

Four students studied reaction of zinc and sodium carbonate with dilute hydrochloric acid and sodium hydroxide solutions and presented
their results as follows. The (V) represents evolution of gas and (x) repeljent absence of any reaction
The correct set of observations is that of student​

Answer 1

Explanation:

Given -

• students studied reaction of zinc and sodium carbonate with dilute hydrochloric acid and sodium hydroxide solutions and presented their results as follows.
• The (✔) represents evolution of gas
• (❌) represent absence of any reaction

To Find -

• The correct set of observations is that of student.

In Case of Zn :-

As we know that :-

1. Zinc reacts with HCl to form zinc chloride and evolve hydrogen gas

Chemical equation :-

• Zn + 2HCl → ZnCl2 + H2

And

2. Zinc reacts with NaOH to form sodium zincate and evolve hydrogen gas

Chemical equation :-

• Zn + 2NaOH → Na2ZnO2 + H2

Here, we see that Zinc reacts with both HCl and NaOH and evolve Gas.

In Case Of Na2CO3 :-

1. Sodium carbonate reacts with HCl to form sodium chloride, water and carbon dioxide gas.

Chemical equation :-

• Na2CO3 + 2HCl → 2NaCl + H2O + CO2

And

2. Sodium carbonate doesn't reacts with NaOH

Chemical equation :-

• Na2CO3 + NaOH → No reaction.

Here, we see that sodium carbonate evolve Gas with HCl and reaction doesn't place with NaOH.

Hence,

Option A is correct.

Answer 2

Answer:

option a is the answer for the question