what does the heating curve of ethanol look like? im really confused about this...
Here is a generic heating curve as well as a generic cooling curve.
http://www.chemcool.com/regents/physicalbehaviorofmatter/aim10.htm
The heating curve of ethanol describes the temperature changes that occur as ethanol is heated. It provides a graphical representation of the relationship between heat input and temperature. Let's break it down to understand better how to interpret the heating curve of ethanol.
First, it is important to note that ethanol has different phases as it is heated: solid (below its melting point), liquid (between the melting and boiling points), and gas (above its boiling point). The heating curve shows the changes in temperature during each phase transition.
The heating curve typically consists of several parts:
1. Solid Phase (Heating): Initially, as heat is applied to a solid sample of ethanol, the temperature increases steadily. This indicates that the solid ethanol is absorbing heat and gaining energy. The temperature will continue to rise until it reaches the melting point.
2. Melting Point: At the melting point (around -114 degrees Celsius or -173 degrees Fahrenheit), the temperature remains constant. This is because the heat being added is used to overcome the attractive forces between ethanol molecules and break the solid crystal lattice structure. During this phase transition, the added heat does not raise the temperature of the substance; instead, it is utilized for breaking the intermolecular bonds.
3. Liquid Phase (Heating): Once all of the solid has melted, the temperature begins to rise again. The liquid ethanol is now able to absorb the heat and gain energy, leading to an increase in temperature.
4. Boiling Point: At the boiling point (around 78 degrees Celsius or 173 degrees Fahrenheit), the temperature remains constant again. The heat being applied is used to convert the liquid ethanol into a gas. This phase transition is known as vaporization, and the added heat during this stage is used to overcome the intermolecular forces of attraction between ethanol molecules to form a gas.
5. Gas Phase (Heating): After all the ethanol has vaporized, further heat input will cause the temperature to rise once again, indicating an increase in the kinetic energy of the ethanol gas.
It's important to remember that during phase transitions (melting and boiling points), the temperature remains constant because the heat energy is being absorbed for the structural changes of the substance rather than increasing its temperature.
So, the heating curve of ethanol looks like a diagonal line indicating temperature increase during the solid and liquid phases, plateaus (horizontal lines) at the melting and boiling points, and another diagonal line indicating temperature increase during the gas phase.
To observe a heating curve firsthand, you would need to conduct an experiment where temperature is plotted against time as heat is gradually applied to a sample of ethanol.