In this lab you will use the metric system to measure the length, weight, and volume of various objects. You will also measure your pulse rate and become familiar with the use of a bunsen burner.

In Experiment 1 part II.A. you will measure the dimensions of the lab bench (the work space area in a lab) in both inches and centimeters. In order to get an accurate measure of the height of the bench you will have to lower your eye to the level of the counter top when you make your reading.

In the picture above the height of the lab bench (indicated by the arrow) is approximately 36.5 inches or 92.8 cm. Based on this information you can calculate the ratio of centimeters to inches. You can practice this in the tutorial below. Just click on the underlined text below.

In Experiment 1 part II. B. you will weigh several objects, such as a piece of filter paper and a piece of metal called a metal slug. Below is a picture of the balance you will use to weigh these objects.

The picture below shows a reading on the vernier scale of the balance you will use to weigh these objects. The vernier scale is actually two scales in one. The scale on the bottom is a coarse scale and the scale on top is a fine scale. If you look at the picture below you will see that the zero line on the top scale points down to between the 5th and 6th lines between the zero and one on the bottom scale. This tells you the object on the balance weighes somewhere between 0.5 and 0.6 grams. You now use the numbers on the top scale, the fine scale, to get a more precise reading. Look at the lines on the top scale and decide which one of those lines is best aligned with a line from the lower scale. Careful inspection should show you that the 7th line on the top scale is best aligned with a line on the bottom scale. This means that the balance is measuring something weighing 0.57 grams. This number is determined by adding the readings from the upper and lower scales.

0.5 + 0.07 = 0.57

This is in agreement with what we saw when we first looked at the coarse scale, that the value was between 0.5 and 0.6 grams.

Read the vernier scale to the right

and place your reading in the box below.

Your answer should be in the form of

X.XX. (For example: 1.23 )

Click on the button next to the box to

submit your answer.

Experiment 1 Part II.C.

In part II.C. of this lab you will measure a quantity of water using a graduated cylinder (sometimes called a graduate). The graduate will be filled in two different ways, at first water can be added to the graduate by pouring it from another container. Once you have reached a volume close to the desired amount, in this case this will be 7.0 mL, you will switch to using a dropper to add the last several drops of water. This will insure greater accuracy in your measurement of the volume. The picture below illustrates the addition of water to the graduate using a dropper.

Experiment 1 Part II.D.

In this section you will take your own pulse. As shown below, place two or three fingers on your wrist and feel for your pulse. Do this now. You will be asked to determine your pulse rate in heartbeats per minute.

Experiment 1 Part II.F.

In this section you light and adjust the flame of a bunsen burner. The bunsen burner will be used throughout the course and it is important that you become familar with its use. Below is a link to a video demonstrating the process of lighting the bunsen burner and adjusting the air intake to the flame. Click on the link below to download the video.

The flame of a bunsen burner is the result of a chemical reaction between the air in the room and the natural gas being released through the bunsen burner. This reaction is called a combustion reaction. The visible part of the flame is the result of very hot gases being released from the combustion reaction. Since the reaction takes place between the air and the natural gas, the interior of the flame (where there is very little air and a great deal of natural gas) is not very hot, because the reaction does not take place here (due to a lack of oxygen.) It is only the outside surface of the flame that is very hot. This can be demonstrated by placing a match inside the flame. The match is supported by a pin which is pushed through it. The pin rests on the top of the barrel of the bunsen burner supporting the match inside the flame. Remarkably, the match does not light (because it does not get very hot) while it rests inside the flame. In the picture below a match head is seen as a white dot in the center of the flame on the right.