Which of the following substances could be heated from 20°C to 100°C most quickly? Assume identical heat sources are used on all substances.
Specific Heat (J/g degrees C)
Gold: 0.1291
Platinum: 0.1326
Silver: 0.2350
Tin: 0.2274
Can you please explain how you figured it out?
Gold
Au, Pt, Sn, Ag in that order.
q = mass x specific heat x delta T
Solve for specific heat or sp.h.
sp. h. = q/m*delta T
So for the same m and delta T, small sp.h. requires small q; large sp.h. require large q.
But you could think of an example and get the same result. If I heat 100 g H2O and stick my finger in the pot of water at the end of 10 seconds,do you think I will burn my finger? Probably not. If I heat a 100 gram piece of metal (like Fe, Sn, Au, etc) and touch my finger to it at the end of 10 seconds I can guarantee you I will have a blister on my finger. Water has a sp.h. of 4.184 J/gram while the metals are about 0.1 to 0.2 J/g. So small sp. h. materials heat up very fast with very little heat.
A piece of copper (C=0.385 J/goC) has an initial temperature of 95oC. When the metal is placed in 79.1g of water that is at an initial temperature of 22.3oC, the temperature rises by 9.7oC. What is the mass of the metal? (Water has a specific heat of 4.18 J/goC) Round to 1 decimal place. No units in your final answer
To determine which substance could be heated from 20°C to 100°C most quickly, we need to compare their specific heats. The specific heat of a substance represents the amount of heat energy required to raise the temperature of one gram of the substance by one degree Celsius.
The formula to calculate the heat energy needed to increase the temperature of a substance is:
Q = m * c * ΔT
Where:
Q = heat energy (in Joules)
m = mass of the substance (in grams)
c = specific heat of the substance (in J/g°C)
ΔT = change in temperature (in °C)
In this case, we're assuming that the masses of the substances are the same since the question states that identical heat sources are used on all substances. Therefore, we can disregard the mass (m) from our analysis.
To determine which substance could be heated most quickly, we need to compare the specific heats (c) of the substances. The substance with the lowest specific heat will require the least amount of heat energy to raise its temperature.
Comparing the data given:
Gold: 0.1291 J/g°C
Platinum: 0.1326 J/g°C
Silver: 0.2350 J/g°C
Tin: 0.2274 J/g°C
From these values, we can see that Gold has the lowest specific heat (0.1291 J/g°C), followed by Platinum (0.1326 J/g°C), and then Silver (0.2350 J/g°C). Tin (0.2274 J/g°C) has the highest specific heat among the given substances.
Therefore, Gold would be heated most quickly from 20°C to 100°C, as it requires the least amount of heat energy relative to its mass.