Make a graph of temperature vs time What does the graph look

Make a graph of temperature vs. time. What does the graph look like? Comment on the shape of the graph; include the reasons for the sudden drop in temperature after the first addition of ice, and why plateaus and temperature rise may occur.

Solution

Ans

(i) The graph looks like a cooling curve observed during a cooling experiment like ice is dropped in hot water/

solution.

(ii) Shape of the graph:

Initially there is a sharp fall from 33.4⁰ C in t=0s to 25.5 ⁰C in t=30s

Then there are some variations in the form of plateaus and rise till it reaches the

fnal temperature at 18.6⁰C.

(iii) Explanation of the shape:

When ice is added to hot water/solution, a part of the heat from the water/ solution melts the ice.

This causes the initial drop in the temperature.

However, the rest of the water/ solution is still warm. A part of the heat from this water/solution

is used in heating up the melted ice. This in turn cools the hot water/ solution.

The results are manifested as plateaus and rises.

With time the final temperature is attained which is same as the ambient temperature.