If mass of apparatus is kept constant, mass of reactants is not equal to products.

Answer

To determine whether the statement "If mass of apparatus is kept constant, mass of reactants is not equal to products" is true or false, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Law of Conservation of Mass**:
- The law states that in a closed system, the total mass of reactants before a chemical reaction must equal the total mass of products after the reaction. This means that mass is neither created nor destroyed in a chemical reaction.

2. **Identify the Role of Apparatus**:
- The mass of the apparatus used in a chemical reaction does not affect the mass of the reactants or products. The apparatus may hold the reactants, but it does not change their mass during the reaction.

3. **Analyze the Given Statement**:
- The statement claims that if the mass of the apparatus is constant, the mass of reactants is not equal to the mass of products. This implies a violation of the law of conservation of mass.

4. **Evaluate with an Example**:
- Consider the reaction of hydrogen and oxygen to form water:
- 2H₂ + O₂ → 2H₂O
- The mass of the reactants (4 grams of hydrogen and 32 grams of oxygen) equals 36 grams.
- The mass of the products (2 molecules of water, each with a mass of 18 grams) also equals 36 grams.
- This example illustrates that the mass of reactants equals the mass of products, regardless of the apparatus used.

5. **Conclusion**:
- Since the mass of reactants should always equal the mass of products according to the law of conservation of mass, the original statement is **false**.

### Final Answer:
The statement "If mass of apparatus is kept constant, mass of reactants is not equal to products" is **false**.

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