Question

X reacts with calcium carbonate giving $C{O}_2$ and $H_{2}O$ and turns methyl orange to:

• A. yellow
• B. red
• C. no color change
• D. pink

Answer 1

The correct option is B

Explanation of correct option.

1. When an acid reacts with metal carbonate, it releases $C{O}_2$ and $H_{2}O$. Methyl

2. For example, the reaction between calcium carbonate $CaCO{}_3$ and hydrochloric acid $HCl$

3. $CaCO{}_3+HCl⟶CaCl{}_2+H{}_{2}O+CO{}_2$

4. From the above reaction, it is clear that the substance X is Acid

5. Methyl orange is a synthetic indicator. It turns red with acid and yellow with base. Hence, with X used in the above example, it turns red as X is an acid.

Explanation of incorrect option

1. Methyl orange shows yellow colour with a base. Since substance X is an acid, therefore, it cannot show yellow colour.

2. Methyl orange turns red with acid and yellow with base, it does not show pink colour in any condition.

3. Methyl orange shows no colour change only in the case of neutral.

Conclusive statement- Option B is correct.