UNIT 11Making Lab Reports

Objective: After completing this lesson you will be able to :

- know a format for lab report- explain what you did in experiment- make lab reports using past tense

Lab reports are an essential part of all laboratory courses and usually a significant part of your grade. If your instructor gives you an outline for how to write a lab report, use that. Here's a format for a lab report you can use if you aren't sure what to write or need an explanation of what to include in the different parts of the report. A lab report is how you explain what you did in experiment, what you learned, and what the results meant. Here is a standard format for a report on an experiment.

Task 1Complete the missing titles by choosing the words from the list.

a. Referencesb. Materials / Apparatusc. Title Paged. Datae. Titlef. Methodsg. Figures and Graphsh. Conclusionsi. Resultsj. Discussion or Analysisk. Introduction/ Purpose / Objectives

.................. (1)Not all lab reports have title pages, but if your instructor wants one, it would be a single page that states:

The title of the experiment. Your name and the names of any lab partners. Your instructor's name. The date the lab was performed or the date the report was submitted.

.................. (2)The title says what you did. It should be brief (aim for ten words or less) and describe the main point of the experiment or investigation. An example of a title would be: "Effects of

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Ultraviolet Light on Borax Crystal Growth Rate". If you can, begin your title using a keyword rather than an article like 'The' or 'A'. .................. (3)Usually the Introduction is one paragraph that explains the objectives or purpose of the lab. In one sentence, state the hypothesis. Sometimes an introduction may contain background information, briefly summarize how the experiment was performed, state the findings of the experiment, and list the conclusions of the investigation. Even if you don't write a whole introduction, you need to state the purpose of the experiment, or why you did it. This would be where you state your hypothesis. .................. (4)List everything needed to complete your experiment. .................. (5)Describe the steps you completed during your investigation. This is your procedure. Be sufficiently detailed that anyone could read this section and duplicate your experiment. Write it as if you were giving direction for someone else to do the lab. It may be helpful to provide a Figure to diagram your experimental setup. .................. (6)Numerical data obtained from your procedure usually is presented as a table. Data encompasses what you recorded when you conducted the experiment. It's just the facts, not any interpretation of what they mean. .................. (7)Describe in words what the data means. Sometimes the Results section is combined with the Discussion (Results & Discussion). .................. (8)The Data section contains numbers. The Analysis section contains any calculations you made based on those numbers. This is where you interpret the data and determine whether or not a hypothesis was accepted. This is also where you would discuss any mistakes you might have made while conducting the investigation. You may wish to describe ways the study might have been improved. .................. (9)Most of the time the conclusion is a single paragraph that sums up what happened in the experiment, whether your hypothesis was accepted or rejected, and what this means. .................. (10)Graphs and figures must both be labeled with a descriptive title. Label the axes on a graph, being sure to include units of measurement. The independent variable is on the X-axis. The dependent variable (the one you are measuring) is on the Y-axis. Be sure to refer to figures and graphs in the text of your report. The first figure is Figure 1, the second figure is Figure 2, etc. .................. (11)If your research was based on someone else's work or if you cited facts that require documentation, then you should list these references.

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Task 2Here are the instructions for a simple experiment with a magnet. You have just done this experiment. Now write the report. Start like this:

The aim of the experiment was to show why the like poles of a magnet repel and the unlike poles attract. We took ....................Continue1.Why do the like poles of magnets repel and the unlike poles attract?

2. Take a sheet of cardboard, a magnet, a handful of iron fillings and a compass.

3. Put the magnet under the sheet of cardboard and scatter the iron fillings on top of the card.

4. Tap the edge of the card lightly.

5. The iron fillings will make a pattern. They will form a series of loops between the two poles of the magnet.

6. Place the compass on one side of the magnet, and then on the other. You will see that the compass needle follows the loops.

7. This shows that there are lines of force which leave the magnet at one pole and enter it again at the other pole.

Task 3Instructions for tempering a steel chisel1. Take a steel chisel.2. Hold the chisel firmly in a pair of tongs.3. Place the chisel in a furnace.4. Heat it to 850 degrees Centigrade.5. Take it out of the furnace.6. Quench it in tepid water.7. Clean the tool with emery cloth.8. Gently re-heat it over a bunsen burner.9. When the metal reaches the required temperature, quench it again.

Now turn these instructions into a report, like this:

First we took a steel chisel. We .........

Task 4 Read the following dialogue between a teacher and a student.Metals have different properties, which make them suitable for different jobs. What properties do you think these common metals have: copper, cast iron, lead, aluminium, steel?

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T : This is a bar of low carbon steel-black or mild steelThis is a bar of high carbon steel known as silver steel. The carbon content is approximately 1%. The mild steel has only 0.1%. Now what I’m going to do today is to see what effect heating has on these two pieces of steel.First, we put them in a vice., then using uniform hammer blows, we will see how many blows it takes to bend them to 90°. Keep count.So how many blows for the high carbon steel?

S : 17T : And for the low carbon steel?S : 9T : Now I’m going to heat the other ends of these two bars to a cheey red. Can you tell

me what temperature that will be?S : 800 degrees?T : Yes, 800 or 850 degrees Centigrade. Now I’ll put them both in the furnace.

So now we’ve heated the bars to a cherry red and quenched them in a special type of oil. Now we can put them back in the vice. Count how many blows. This is the low carbon steel. How many blows?

S : 9 again.T : Fine. And now the silver steel. So one blow and it fractured.

What effect has heating and quenching had on these two pieces of steel?S : Well, the shiny steel won’t bend anymore.T : Yes, it’s made that one – the silver steel – very brittle. But not the mild steel. so

why has this happened?

Task 5 Make a chart like this. Fill it in using the information from the experiment.

Aim of the experiment:

Type of steel low carbon high carbonBlows to bend to 90° before heating: after heating:Effect noted:

Task 6There are several names given for each of the two pieces of steel. Write them down in two lists.

Task 7Find words in the dialogue which mean the same as:1. easily broken; it won’t bend2. to break3. to make something hot4. to make something cooler

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5. hit6. reflecting light7. the same; standar8. about

Task 8We want to make a report on the experiment from the dialogue. The tense we use is the past tense. In the following report, put the verbs into the correct tense and use the information from your chart to complete the report.

The experiment (be) .......... to show ............... on steels with different ............... contents. The teacher (take) .......... two pieces of steel, one with ............... and the other with ............... . He (put) .......... them in a ............... and, using ............... he (bend) .......... them to ............... . The mild steel bar (take) .......... ............... blows and the silver steel ............... . then the teacher (heat) .......... the bars to ............... and (quench).......... them in ................ he (place) .......... them in the vice again and (hit) .......... them with the hammer to try to bend the other ends. The ............... again (take) .......... ............... blows to bend it, but the ............... (break) .......... with just ............... . We noted, then, that ............... and ............... (make) .......... the silver steel very ..............., but that the ...............(show) ........... no change. We (conclude) .......... that this effect was due to the differnce in ............... content of the two steels.

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