Specific Heat Capacity

Question

Science students are studying specific heat capacity and trying to make decisions about what materials would be good insulators and conductors. Student groups set up this experiment. Materials/group: ~thermometer ~Stopwatch ~4 empty soda cans to be filled:
One can filled 1/2 way with water One can filled 1/2 way with sand One can filled 1/2 way with iron filings One empty can
~Tub of ice water Procedures: 1. Record the initial temperatures inside each can. 2. Place the four cans into the ice water bath, leaving them for 5 minutes. 3. Remove the cans and record the final temperatures of each can.
Specific Heat Capacity
Material Specific heat capacity J/
C at 25C
Copper 0.385
Iron 0.450
Sand 0.830
Aluminum 0.897
Air 1.012
Cork 2.000
Water 4.181
Question 1
PART A
Consider the data table as well as the experimental design. Which of the four cans should have the greatest change in temperature after five minutes?
Responses
A airair
B sandsand
C waterwater
D iron filingsiron filings
Question 2
PART B
Once the activity had been completed, the instructor asked the students to design an insulated container they could use to keep 100mL of water hot. The only stipulation was that the insulator had to be a solid. The team that kept the water hot, at least 85C, for the longest amount of time, would win a prize. If you were participating, what would you use as your insulator?
Responses
A aluminumaluminum
B corkcork
C sandsand
D water

Answer 1

Question 1 - Part A

To determine which of the four cans should have the greatest change in temperature after five minutes, we need to consider the specific heat capacities of the substances inside each can:

• Water (Specific Heat Capacity = 4.181 J/g°C): Water has a high specific heat capacity, meaning it can absorb a lot of heat without experiencing a large change in temperature.
• Sand (Specific Heat Capacity = 0.830 J/g°C): Sand has a moderate specific heat capacity. It will heat up more quickly than water.
• Iron Filings (Specific Heat Capacity = 0.450 J/g°C): Iron has a lower specific heat capacity compared to sand and water; thus it will experience a significant change in temperature.
• Air (Not filled, so its effect here is negligible): Air has a specific heat capacity of 1.012 J/g°C, but since it's not contained in a can, its role here is limited.

Given these specifics, the material with the lowest specific heat capacity will likely have the greatest change in temperature because it can absorb heat more efficiently with less energy required.

Correct Answer: D - iron filings

Question 2 - Part B

When designing an insulated container to keep 100 mL of water hot (at least 85°C) for the longest amount of time, we should consider the material with the best insulating properties. The options provided are:

• A. Aluminum: Metal with good thermal conductivity, not an ideal insulator.
• B. Cork: A natural insulator known for its low thermal conductivity and ability to resist heat transfer, making it effective for insulation.
• C. Sand: While it has a higher specific heat capacity than some options, it's not as effective as an insulator compared to materials like cork.
• D. Water: Water is a good thermal conductor and not suitable as a solid insulator.

Given these considerations, cork would be the best choice for insulation as it effectively reduces heat transfer and would help keep the water warm.

Correct Answer: B - cork