Question

Observe the following graph and answer the following questions:

What does the graph represent?

Hint:

The heating curve of water shows phase changes at constant temperature. The line AB represents melting at \(0^\circ C\), while BC represents heating of water up to \(100^\circ C\).

Answer 1

Step 1: Understanding the graph
- The graph shows temperature vs. time for water during heating. - It illustrates the phase transitions of water from solid to liquid and then to gas. - The flat portions indicate phase changes, where heat energy is used to break intermolecular bonds instead of increasing temperature. Thus, this graph is a heating curve that demonstrates the phase transitions of water. (b) What does the line AB represent? \hfill [1] % Correct Answer Correct Answer: The line AB represents the melting process where ice converts into water at \(0^\circ C\). % Solution Solution:
Step 1: Identifying the line AB
- The segment AB is a horizontal line, indicating a phase change. - This shows the melting of ice at a constant temperature of \(0^\circ C\). - During this process, heat is absorbed to break the bonds in ice, converting it into liquid water. Thus, AB represents the melting of ice into water at \(0^\circ C\). (c) What does the line BC represent? \hfill [1] % Correct Answer Correct Answer: The line BC represents the heating of water, where its temperature increases from \(0^\circ C\) to \(100^\circ C\). % Solution Solution:
Step 1: Identifying the line BC
- The segment BC is an upward-sloping line, indicating an increase in temperature. - This represents the heating of water after complete melting. - Water absorbs heat energy, which increases its temperature from \(0^\circ C\) to \(100^\circ C\). Thus, BC represents the heating of water from \(0^\circ C\) to \(100^\circ C\), preparing for boiling.