A limiting reagent is the reactant which gets completely ..........during the reaction.

Answer

**Step-by-Step Text Solution:**

1. **Understanding the Concept of Limiting Reagent:**
- A limiting reagent (or limiting reactant) is the substance that is completely consumed when the chemical reaction goes to completion. This means that it limits the amount of product that can be formed because once this reactant is used up, the reaction stops.

2. **Filling in the Blank:**
- The question states: "A limiting reagent is the reactant which gets completely __________ during the reaction."
- The appropriate word to fill in the blank is "consumed."

3. **Example for Clarification:**
- Consider the reaction between nitrogen (N₂) and hydrogen (H₂) to form ammonia (NH₃):
\[ N_2 + 3H_2 \rightarrow 2NH_3 \]
- According to stoichiometry, 1 mole of nitrogen reacts with 3 moles of hydrogen.

4. **Given Amounts:**
- Suppose we have 1 mole of nitrogen and 2 moles of hydrogen.
- From stoichiometry, to completely react with 1 mole of nitrogen, we need 3 moles of hydrogen. However, we only have 2 moles of hydrogen available.

5. **Determining the Limiting Reagent:**
- Since we need 3 moles of hydrogen but only have 2, hydrogen is the limiting reagent.
- The nitrogen will not be completely consumed because there is not enough hydrogen to react with it.

6. **Conclusion:**
- Therefore, in this reaction, hydrogen is the limiting reagent because it is completely consumed, while some nitrogen will remain unreacted.

**Final Answer:**
A limiting reagent is the reactant which gets completely **consumed** during the reaction.

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