Specific Heats for Several Common Metals J g^-1 °C^-1
AI - 0.903 Cu- 0.385 Fe- 0.449 K- 0.757 Pb- 0.128 Zn- 0.388
b) Which metal requires more heat per gram to warm it up? Explain your answer.
c) Which metal would be the warmest if an equal mass of each metal absorbed the same amount of heat? Explain.
d) How many joules of energy are needed to heat a 125 gram chunk of copper from an initial temperature of 10.0 °C to a final temperature of 95.0 °C?
e) If the same quantity of heat from your answer to (c) is used to heat a 125 gram piece of aluminum initially at 10.0 °C, what will be the final temperature?
f) Does the final temperature you calculated in (d) for the aluminum make sense? Explain.
b) To determine which metal requires more heat per gram to warm it up, we need to compare their specific heats. The specific heat is the amount of heat required to raise the temperature of 1 gram of a substance by 1 degree Celsius. In this case, we are given the specific heat values for each metal.
From the given values, we can see that the metal with the highest specific heat is AI with a value of 0.903 J g^-1 °C^-1. Therefore, AI requires more heat per gram to warm it up compared to the other metals.
c) To determine which metal would be the warmest if an equal mass of each metal absorbed the same amount of heat, we need to compare their specific heats. The metal that requires less heat per gram has a higher temperature increase.
In this case, we can see that the metal with the lowest specific heat is Pb with a value of 0.128 J g^-1 °C^-1. Therefore, if an equal mass of each metal absorbed the same amount of heat, Pb would have the highest temperature increase and would be the warmest.
d) To calculate the amount of energy needed to heat a 125 gram chunk of copper from 10.0 °C to 95.0 °C, we can use the formula:
Energy = mass * specific heat * temperature change
Substituting the known values:
Energy = 125 g * 0.385 J g^-1 °C^-1 * (95.0 °C - 10.0 °C)
Using this equation, the amount of energy needed would be:
Energy = 125 g * 0.385 J g^-1 °C^-1 * 85.0 °C
e) To find the final temperature of a 125 gram piece of aluminum when the same quantity of heat is used as in question (c), we can use the formula:
Energy = mass * specific heat * temperature change
Since the amount of energy is the same, we can set the two equations equal to each other:
Mass of AI * specific heat of AI * temperature change of AI = Mass of Al * specific heat of Al * temperature change of Al
We are given the mass of Al (125 grams), the initial temperature (10.0 °C), and the specific heat of Al (we need to find this).
Now we can rearrange the equation to solve for the final temperature:
Final temperature = initial temperature + (Energy / (mass * specific heat))
f) We can determine if the final temperature calculated in (d) for aluminum makes sense by comparing it to the melting point of aluminum. If the final temperature is above the melting point, it does not make sense because aluminum would melt.
If the final temperature is below the melting point, it makes sense because aluminum would remain solid. We would need to know the specific heat of aluminum to further analyze this information.