A student of performs a titration with different burettes and finds titre values of `25.2 mL`, `25.25 mL`, and `25.0 mL`. The number of significant figures in the average titre value is …..

Explanation

To determine the number of significant figures in the average titre value calculated from the given measurements, we can follow these steps:

### Step-by-Step Solution:

1. **List the Titre Values**:
The titre values obtained from the titration are:
- 25.2 mL
- 25.25 mL
- 25.0 mL

2. **Calculate the Average**:
To find the average titre value, we first add the titre values together:
\[ 25.2 + 25.25 + 25.0 = 75.45 \text{ mL} \]
Next, we divide the sum by the number of values (which is 3):
\[ \text{Average} = \frac{75.45}{3} = 25.15 \text{ mL} \]

3. **Determine Significant Figures**:
Now, we need to determine the number of significant figures in the average titre value. The rule for significant figures in addition and subtraction states that the result should be reported with the same number of decimal places as the measurement with the least number of decimal places.

- 25.2 mL has **1 decimal place**.
- 25.25 mL has **2 decimal places**.
- 25.0 mL has **1 decimal place**.

The measurement with the least number of decimal places is 25.2 mL and 25.0 mL, both having **1 decimal place**.

4. **Final Result**:
Therefore, the average titre value should be reported with **1 decimal place**. Thus, the average titre value is:
\[ 25.2 \text{ mL} \]
The number of significant figures in the average titre value is **3** (since 25.2 is considered to have 3 significant figures).

### Conclusion:
The number of significant figures in the average titre value is **3**.

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