Assignment, Lab: Thermal Energy Transfer

7. A 50 g sample of an unknown metal is heated to 90.0 °C. It is placed in a perfectly insulated container along with 100 g of water at an initial temperature of 20°C. After a short time, the temperature of both the metal and water becomes equal at 25°C. The specific heat of water is 4.18 J/g°C in this temperature range. What is the specific heat capacity of the metal? Record your answer with two significant figures.

- 0.64 J/g°C

3. When measuring a calorimeter, the initial temperature of a metal is 70.4°C. The initial temperature of the water is 23.6°C. At the end of the experiment, the final equilibrium temperature of the water is 29.8°C. - What is the final temperature of the metal? - What is the temperature change of the water? - What is the temperature change of the metal?

- 29.8°C - 6.2°C - -40.6°C

5. In an experiment, 50 g of each material were placed in a calorimeter with the same starting water volume and temperature. Which is the best interpretation of the chart.

- Different materials have different abilities to transfer energy.

9. Which are ways to improve the design of this experiment? Check all that apply.

- Increase the sample size from 6 cups to 12 cups of sand and water. - Use more precise digital thermometers. - Use more precise scales that measure to the hundredth of a gram.

8. Which are potential sources of error in the experiment? Check all that apply.

- estimating temperature to the nearest tenth of a degree - estimating the mass of the sample to the nearest tenth of a gram - the position of the cups of sand and water under the heat lamp

2. Based on what you have learned about the units for measuring thermal energy, complete the following passage. -The unit often used in chemistry and physics to measure energy, such as for work or electrical current is the __________. -We can also use this unit, as we did in this lab, for measuring _________. -This is a property that is quantified by the energy needed per _________ of material to raise the temperature by one _________. -The unit of this measure is therefore _________.

- joule - specific heat - gram - degree Celsius -J/g°C

1. Throughout the reflection, make sure you have a copy of the 'Student Guide' and your data tables. Use the drop-down menus to complete the statements. - The independent variables in Part I, the ones intentionally manipulated, are the ________. - The independent variable in Part II, the one that is intentionally manipulated is the _________. - The dependent variable for both Parts I and II, the one that you measure the response in, is the ________.

- mass and type of material - type of material - temperature

4. Which graph best demonstrates the general relationship between mass and temperature, similar to the trend of thermal energy absorbed by your sand and water samples?

- the first graph

6. Use this chart showing the different specific heat of various materials to answer the questions. -Which materials have the highest specific heat? - Which material has the lowest specific heat? - Which material has the ability to absorb twice as much heat as aluminum when placed in the same environment of mass and temperature?

- water - lead - wood