`561 "dm"^3` of a gas at STP is filled in a `748 "dm"^3` container. If temperature is constant , calculate the percentage change in pressure required.

Explanation

To solve the problem, we need to calculate the percentage change in pressure when a gas initially occupying a volume of 561 dm³ at STP is transferred to a larger container of 748 dm³, while keeping the temperature constant.

### Step-by-Step Solution:

1. **Identify the Initial and Final Volumes:**
- The initial volume (V1) of the gas is given as 561 dm³.
- The final volume (V2) of the container is given as 748 dm³.

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