I have two questions on my review study guide that go like this:
1) What is the equation for calculating the energy change that occurs when a substance changes state?
2) What is the equation for calculating the energy change that occurs when a substance increases in temperature?
Wouldn't they both use the same equation, q = mcÄT?
That's supposed to be q = mc(delta)T
change of temperature is correct at q = mc(delta)T. But the equation for changing state is
q = mass x heat fusion for melting (change from solid to liquid state).
q = mass x heat vaporization for boiling (change from liquid to vapor state).
Ohhhh I see now! Thanks so much!! :)
Yes, both questions can be answered using the same equation, which is q = mcΔT.
To explain the equation, here's what each symbol represents:
- q: This represents the amount of energy transferred in the form of heat.
- m: This represents the mass of the substance undergoing the change.
- c: This represents the specific heat capacity of the substance, which is a property of the material and measures how much energy is required to change its temperature.
- ΔT: This represents the change in temperature of the substance.
Now let's dive into the answers to the questions:
1) What is the equation for calculating the energy change that occurs when a substance changes state?
When a substance changes state (i.e., undergoes a phase change), such as from a solid to a liquid or a liquid to a gas, there is a specific amount of energy required. The equation q = mcΔT can be used to calculate this energy change. Here, ΔT would represent the temperature change during the phase transition instead of the overall increase in temperature.
2) What is the equation for calculating the energy change that occurs when a substance increases in temperature?
When a substance increases in temperature, without undergoing a phase change, the equation q = mcΔT can also be used. In this case, ΔT would represent the change in temperature from the initial temperature to the final temperature.
So, to summarize, for both questions, the equation q = mcΔT can be used. The only difference is what ΔT represents – either the change in temperature during a phase change or the overall change in temperature.