Question

what was happening to the H20 when the lines on the graph were mostly flat? What kind of energy was being added to the system?

Answer 1

That's latent heat of vaporization.

• Water boils at 100°C
• The graph increases still 100°C
• once it reaches boiling point it yields a straight line because of latent heat after all molecules are evaporated then the graph rises back

Answer 2

Answer: A heating curve graphically represents the phase transitions that a substance undergoes as heat is added to it.

The plateaus on the curve mark the phase changes. The temperature remains constant during these phase transitions.

Water has a high boiling point because of the strong hydrogen bonds between the water molecules; it is both a strong hydrogen bond donor and acceptor.

The first change of phase is melting, during which the temperature stays the same while water melts. The second change of phase is boiling, as the temperature stays the same during the transition to gas

Step-by-step explanation: