Lab 6: Generating and Burning Hydrogen Gas

October 9, 2008 Hydrogen "Pop" Test Julie Anne A. Day 1, Prd 4

Purpose: To observe what happens to hydrogen when it's burnt

Materials:

• big test tube
• small test tube
• test tube rack
• candle
• splint
• matches
• hydrochloric acid
• magnesium
• test tube holder

Procedure:

1. Put the hydrochloric acid in the small test tube. Then, put in the magnesium.
2. After putting in the magnsium, cover the test tube with the bigger test tube.
3. Wait patiently for about 30 seconds or a minute.
4. While waiting, light the candle and light the splint with the candle.
5. Take the big test tube off carefully without turning it upside down.
6. Insert the burning splint in the big test tube.
7. Observe.

Data and Observations:

• When the magnesium was inserted to the test tube with hydrochloric acid, bubbles were produced around it and hyrdrogen gas was being produced. Also, as it stayed in the hydrochloric acid, it lost its colour. It turned from black to white. The bubbles, while they were bubbling, moisture built up on the faces of the big test tube that covered the small test tube.

• The burning splint, when it was put in the big test tube, I saw this sort of mist like smoke produced in the big test tube. Also, when the burningn splint was put in the bigger test tube, a loud pop was produced. I thought the test tube would vibrate but it didn't. I didn't feel thing while holding the large test tube.

Questions:

• How can a burning splint be used to test the presence of hydrogen gas?

It can be used to test the presence of hydrogen since maybe, it reacts with the hydrogen gas.

Conclusion:

I learned in today's experiment that by combining magnesium with hydrochloric acid, you can produce hydrogen gas. I didn't know that before. Also, I learned that the "pop" that is produced when the burning splint was put in a test tube with hydrogen gas, is harmless and does not vibrate. I think the pop occured because the flame in the burning splint reacted with hydrogen, since hydrogen belonged to the most reactive chemicals, as my teacher said.

***This experiment can be represent in HCl + Mg ----> MgCl2 + H2 = pop