A highly viscous liquid was heated from `10^(@)C` to `14^(@)C`. The per cent decrease in viscosity will be about

Explanation

To solve the problem of finding the percentage decrease in viscosity when a highly viscous liquid is heated from \(10^\circ C\) to \(14^\circ C\), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Temperature Change**:
- The initial temperature (\(T_1\)) is \(10^\circ C\) and the final temperature (\(T_2\)) is \(14^\circ C\).
- Calculate the change in temperature (\(\Delta T\)):
\[ \Delta T = T_2 - T_1 = 14^\circ C - 10^\circ C = 4^\circ C \]

2. **Understand the Relationship Between Temperature and Viscosity**:
- It is given that for every degree Celsius increase in temperature, the viscosity decreases by 2%.

3. **Calculate the Total Percentage Decrease in Viscosity**:
- Since the temperature increased by \(4^\circ C\), we can calculate the total decrease in viscosity:
\[ \text{Percentage decrease} = \Delta T \times 2\% = 4 \times 2\% = 8\% \]

4. **Conclusion**:
- Therefore, the percentage decrease in viscosity when the liquid is heated from \(10^\circ C\) to \(14^\circ C\) is \(8\%\).

### Final Answer:
The percentage decrease in viscosity is approximately **8%**.

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