Which of the following statement is incorrect ?

Options

A. Almunium reacts with excess NaOH to give `Al(OH)_(3)`
B. `NaHCO_(3)` on heating gives `Na_(2)CO_(3)`
C. Pure sodium metal dissolves in liquid ammonia to give blue solution
D. NaOH reacts with glass to give sodium silicate

Answer

To determine which statement is incorrect among the given options regarding the reactions involving sodium hydroxide and other substances, we will analyze each statement step by step.

### Step 1: Analyze the first statement
**Statement:** Sodium hydroxide reacts with glass to give sodium silicate.

**Analysis:**
- Glass is primarily composed of silica (SiO2).
- The reaction of sodium hydroxide (NaOH) with silica (SiO2) can be represented as:
\[ \text{SiO}_2 + 2 \text{NaOH} \rightarrow \text{Na}_2\text{SiO}_3 + \text{H}_2\text{O} \]
- This indicates that sodium hydroxide does indeed react with glass (silica) to produce sodium silicate (Na2SiO3) and water.

**Conclusion:** This statement is correct.

### Step 2: Analyze the second statement
**Statement:** When we heat NaHCO3, it gives Na2CO3.

**Analysis:**
- Heating sodium bicarbonate (NaHCO3) results in the following reaction:
\[ 2 \text{NaHCO}_3 \rightarrow \text{Na}_2\text{CO}_3 + \text{H}_2\text{O} + \text{CO}_2 \]
- This shows that sodium bicarbonate decomposes to form sodium carbonate (Na2CO3), water, and carbon dioxide.

**Conclusion:** This statement is correct.

### Step 3: Analyze the third statement
**Statement:** Pure sodium metal dissolved in liquid ammonia gives a blue solution.

**Analysis:**
- When sodium metal is dissolved in liquid ammonia (NH3), it forms a deep blue solution due to the formation of sodium amide and solvated electrons.
- The reaction can be represented as:
\[ \text{Na} + \text{NH}_3 \rightarrow \text{Na}^+ + \text{e}^- + \text{NH}_2^- \]
- The presence of solvated electrons gives the solution its characteristic blue color.

**Conclusion:** This statement is correct.

### Step 4: Analyze the fourth statement
**Statement:** NaOH reacts with glass to give sodium silicate.

**Analysis:**
- As previously analyzed in Step 1, sodium hydroxide reacts with silica (SiO2) to produce sodium silicate (Na2SiO3) and water.
- The reaction is valid and correctly represents the interaction of NaOH with glass.

**Conclusion:** This statement is correct.

### Final Conclusion
After analyzing all four statements, we find that all of them are correct. However, the question specifically asks for the incorrect statement. Based on the analysis, the first statement regarding aluminum and sodium hydroxide is incorrect because it misrepresents the products formed in the reaction.

### Summary of Incorrect Statement
The incorrect statement among the options is the one that suggests a misrepresentation of the reaction products when aluminum reacts with sodium hydroxide.