Chapter 19.3, Problem 24R

To determine

To calculate: the time that is taken by reaction to reach $0°\text{C}$ .

Answer to Problem 24R

13 minute.

Explanation of Solution

Given:

Initial temperature is $26°\text{C}$ .

Final temperature is $0°\text{C}$ .

Decrease of temperature per minute is $2°\text{C}$ .

Formula used:

The formula for time is given by,

  $t=\frac{\text{difference}\text{in}\text{temperature}}{\text{change}\text{of}\text{temperature}}$... (1)

Calculation:

Substitute $26°\text{C}$ for initial temperature, $0°\text{C}$ for final temperature and $2°\text{C}$ for change of temperature/ minute in equation (1),

  $\begin{array}{l}t=\frac{\left(26°-0°\right)\text{C}}{2°\text{C/min}}\\ t=13\min \end{array}$

Conclusion:

Hence, the required time is 13 minute.