Instructions for Experiment

Determining Unknown Metals from Specific Heat

Your lab report will consist of four sections: Introduction, Results, Discussion and Questions. The lab report must be typed using a 12 point font. Reports not typed will lose points. No excuses. Cursive or ornate fonts are not acceptable. Be careful with spelling and grammar. Poor spelling and grammar detract from a reader’s overall impression of the report. This is group lab report.

Your report will be graded out of thirty points possible as follows:

Introduction. (3 points) The introduction should include a clearly stated purpose. This report concerns the determination of the identity of unknown metals from their specific heats. You should have a clearly stated hypothesis as to what you think the identity of each of the metals that you tested and why you believe your hypothesized identity.

Results. (7 points) This section should include your results:

Show your data and calculation for the determination of the heat transferred from the metal to the water in the calorimeter.

Show your data and calculation for the determination of the specific heat of the metal.

Results should include what your group thinks your metal is.

Discussion (7 points):

This section should contain three paragraphs.

The first paragraph should be a summary of the experiment. This should require at least 5-6 sentences and no less than 75 words.

The second paragraph should discuss your results. Clearly indicate what the results were and how you used your results to decide upon the identity of the unknown metal.

The last paragraph should include a discussion of potential sources of error in your results and suggestions for improvement. You should attempt to distinguish between random and systematic errors. This section should be at least 50 words.

Questions. (10 points – 2 points per question)

Answer the following five questions:

1. Why would it be a good idea to blot the metal from the hot water bath before placing it in the room temperature water?

2. What factors might affect the specific activity determination?

3. A 5.037 g piece of iron heated to 100ºC is placed in a calorimeter that initially contains 27.3 g of water at 21.2°C. If the final temperature is 22.7°C what is the specific heat capacity of the iron?

4. A 25.0347 g piece of nickel is heated to 100°C and placed in a calorimeter that initially contains 125 mL of water at 21.2ºC. What is the final temperature? (you will need to look up the specific heat of nickel.

5. What is the relationship between a metal's specific heat (heat capacity) and its ability to conduct heat or its ability to conduct electricity? What metals would be best suited for cooking utensils and why?

Appearance, Spelling and Grammar (3 points)

More than one spelling error and you will lose a point. For major grammar errors (sentence fragments, run-on sentences, comma splices, etc.), you will lose a point. You will lose points for appearance if you incorporate non-typed material into your report or if you use non-standard paper (e.g. notebook paper) in your report.