Bunsen Burner

Today was our first lab lesson of the year for the Chemistry module. We kicked this lesson off by studying about Bunsen Burners.

Previously, I have seen my primary school teachers lighting bunsen burners but never really tried to light one myself. Mainly because I wasn't given very clear explanation and it seemed really scary at first. I wasn't really sure about the closing and opening of the air holes and when to light the fire etc.

However, after today's lesson, I can definitely say that I have become more confident regarding the lighting of the bunsen burner. Mr Foo gave explicit explanation on how to light it correctly and I got to try it a couple of times.

The following are the steps to lighting the bunsen burner safely:

1) Connect the rubber tubing to the gas tap

2) Check that the air holes are closed (*Leaving air holes open could be dangerous)

3) Turn the gas tap on

4) Position the lighter above the barrel and light it ip

5) Open the air holes SLOWLY to about halfway and even fully, depending on which type of flame you want.

*Leaving the air holes open when lighting up the bunsen burner may result in a strike back.

The next step of the activity was to identify which part of the flame is the hottest

Here'a a picture to give you some idea of how the flame looks like.

When a flame is ignited with a closed air hole, the flame is yellow/orange (A,B). However, as you slowly open the air hole, the flame turns into flame C. The flame in C is called the non-luminous flame. It is really hot.

The parts of the flame we had to measure was the part slightly above the tip of the blue flame (part of the orange flame), tip of the blue flame and the core of the blue flame.

This is the non-luminous blue flame. When I lit it up it produced a noise that was quit loud but it was really really cool.

I am not sure but I actually opened the air hole fully, is it dangerous?

So you can see the tip of the blue flame and the orange flame too. Those are the positions where I used to carry out the experiment.










This was the procedure to carrying out the experiment:

1) Turn on the bunsen burner
2) Use metal tongs to hold copper wire just slightly above the tip of the blue flame
3) Use a stopwatch to time how long it takes for the copper wire to glow red
4) Record the time
5) Repeat steps 2-4 with the copper wire held at the outer blue flame and the inner blue core

This is the results I got:

Thus, the part just above the blue flame is the hottest.

The constant variables for this experiment are:
-The flame itself
-The copper wire

The independent variable is:
-The position of the flame where the copper wire would be placed at

The dependent variable is:
-The time taken for the copper wire to glow red on respective sections of the flame

Mr Foo said that the assumption of this experiment is that the thickness of the copper wire stays the same, since the copper wire would expand when heated!

 This is a picture I took while the copper wire was being heated. You can see that the copper wire actually glows!

The copper wire was melting when I was heating it! There was also a flame on top of it.















Overall, it was a really enriching experience and I got to know more about the process of lighting bunsen burners. It was also really cool to see the copper wire getting heated!