In exoergic reaction, the total mass of products is `………………………..` than the total mass of reactants.

Answer

To solve the question regarding exoergic reactions, we need to understand the relationship between mass and energy in these types of reactions.

### Step-by-Step Solution:

1. **Understanding Exoergic Reactions**:
- Exoergic reactions are chemical reactions that release energy to the surroundings. This energy release can be in the form of heat, light, or other forms of energy.

2. **Mass-Energy Relationship**:
- According to Einstein's mass-energy equivalence principle, expressed by the equation \( E = \Delta mc^2 \), energy (E) and mass (\(\Delta m\)) are interchangeable. When energy is released in a reaction, it implies a change in mass.

3. **Energy Release and Mass Defect**:
- In an exoergic reaction, since energy is released, the change in energy (\(E\)) is negative. This means that the mass of the products is less than the mass of the reactants because some mass has been converted into energy.

4. **Formulating the Mass Relationship**:
- If we denote the total mass of reactants as \( m_{reactants} \) and the total mass of products as \( m_{products} \), the relationship can be expressed as:
\[ m_{products} < m_{reactants} \]
- This indicates that the total mass of the products is less than the total mass of the reactants.

5. **Final Answer**:
- Therefore, we can fill in the blank: "In exoergic reaction, the total mass of products is **less** than the total mass of reactants."