In which of the following reactions, products given are not correct?

Options

A. `(NH_(4))_(2)Cr_(2)O_(7) overset(Delta)to N_(2)+ 4H_(2)O+Cr_(2)O_(3)`
B. `Ba(N_(3))_(2) overset(Delta)to Ba+3N_(2)`
C. `3Mg+N_(2) overset(Delta)toMg_(3)N_(2)`
D. `NH_(4)Cl+NaNO_(2)toNaCl+NH_(3)+NO_(2)`

Answer

To determine which of the given reactions has incorrect products, we will analyze each option step-by-step.

### Step 1: Analyze the first reaction
**Reaction:** \( \text{NH}_4\text{Cr}_2\text{O}_7 \) is heated.

**Expected Products:** The products are \( \text{N}_2 + 4\text{H}_2\text{O} + \text{Cr}_2\text{O}_3 \).

**Analysis:**
- Ammonium dichromate decomposes upon heating to produce nitrogen gas, water, and chromium(III) oxide.
- This reaction is correct.

### Step 2: Analyze the second reaction
**Reaction:** \( \text{BaN}_3 \) (barium azide) is heated.

**Expected Products:** The products are \( \text{Ba} + \text{N}_2 \).

**Analysis:**
- Barium azide decomposes upon heating to yield barium and nitrogen gas.
- This reaction is also correct.

### Step 3: Analyze the third reaction
**Reaction:** \( 3\text{Mg} + \text{N}_2 \) gives \( \text{Mg}_3\text{N}_2 \).

**Expected Products:** The product is \( \text{Mg}_3\text{N}_2 \).

**Analysis:**
- Magnesium reacts with nitrogen gas to form magnesium nitride, which is a combination reaction.
- This reaction is correct.

### Step 4: Analyze the fourth reaction
**Reaction:** \( \text{NH}_4\text{Cl} + \text{NaNO}_2 \) is reacted.

**Expected Products:** The products are \( \text{NaCl} + \text{NH}_3 + \text{N}_2 \).

**Analysis:**
- The correct products of the reaction between ammonium chloride and sodium nitrite are actually \( \text{N}_2 + 2\text{H}_2\text{O} + \text{NaCl} \).
- The expected products given in the question are incorrect because they do not account for the water produced.

### Conclusion
The fourth option is the incorrect reaction. Therefore, the answer is:

**Answer: Option 4 is incorrect.**

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