Science - Metal Reactions Blog

This week in Science we are learning about metals and it's different properties. Most of our experiments that we have done so far are to do with the reactants of metal and acid. Acids react with most metals and, when they do, a salt is produced. Instead we get hydrogen gas. It doesn't matter which metal or which acid is used, if there is a reaction we always get hydrogen gas as well as the salt. Below are the experiments that I got to do in class therefore I wasn't present for one of the experiments.

 Metal + Acid Experiment(s)

When a metal reacts with an acid, the same types of products are always formed. In this experiment the metal we are using is magnesium (mg) and the acid is Sulfuric Acid (H2SO4). We believe that if we mix these two reactants our products are magnesium sulfate plus + hydrogen.

Aim: To show that hydrogen gas is produced when a metal reacts with acid.

Equipment: A test tube, a boiling tube, Bunsen Burner, wooden splint, a bottle of acid, a piece of metal, safety glasses.

Method:

1. Light your Bunsen Burner.

2. Add your sample of metal to your test tube. Add 2mL of acid.

3. Carefully invert the boiling tube above the test tube containing the metal and acid (as shown in the diagram below)

 

4. Hold the test tubes together for a few minutes, allowing time for the inverted boiling tube to fill with gas.

5. When you think the tube is full. your lab partner should light a wooden splint.

6. Carefully, but quickly, tilt the boiling tube full of gas upwards and insert the burning splint into the mouth of the test tube.

Observations: Steam being produced when the metal was added with acid, when the flame came near, it made a pop sound.

Outline how you could tell a chemical reaction was occurring in the test tube: There was steam being produced and the metal was moving around, it was trapped.

Metals and Oxygen

When a metal reacts with oxygen it produces a metal oxide.

In this experiment we used magnesium + oxygen to form magnesium oxide. When a substance burns, the burning process is actually a reaction with oxygen. So when you burn something, you are adding oxygen to it.

Making a Metal Oxide

Aim: To make a metal oxide and observe the difference in properties of the product compared to the reactants.

Equipment: A piece of magnesium, Bunsen Burner, safety glasses, metal scissors tongs. 

Method: 1. Light your Bunsen Burner

                2. Hold your piece of magnesium in the scissor tongs. Ensure you are holding onto the                         very tip of the magnesium. 

                3. Place the other end of the magnesium into the Bunsen flame (at the top of the blue                           flame. 

               4.  When the magnesium begins to burn, do not look directly at it, as the light emitted                              can permanently damage your eyes. 

Observations: When the metal would connect with the blue fire, after it would light up it was as bright as a star but close up then it changed and became a white powder. 

Questions:

1. Describe the physical properties of the magnesium before the reaction?

    Silver, Lustre

2. Describe the physical properties of the oxide formed after the reaction?

   It was ashy and the powder colour was white.

3. Why you shouldn't you look directly at a piece of burning magnesium?

   Because it can harm your eyesight.

4. Complete the word equation for this reaction

    Magnesium + Oxygen = magnesium oxide

Metal Carbonates and Acid -Lime Water Test

In this experiment we used metal carbonate + acid to produce metal salt + water + carbonate.

Aim: To show that carbon dioxide gas is produced when a metal carbonate reacts with acid.

Equipment: Two boiling tubes, delivery tube and bung. Bunsen burner, test tube rack, wooden splint, a bottle of acid, small amount of metal carbonate, test tube tongs, safety glasses.

Method:

1. Light your Bunsen Burner

2. Add a 'pea-sized' amount of the metal carbonate into one of the boiling tubes. 

3. Place this boiling tube into a test tube rack. Ensure you have the bung and delivery tube ready.

4. Add 5 mL of acid to the boiling tube and quickly insert the bung and delivery tube into the mouth of the boiling tube. 

5. Holding the other boiling tube with your tongs, capture the gas produced as shown in the diagram below. 

6. When you think the tube is full, your lab partner should light a wooden splint. 

7. Carefully remove the boiling tube from under the delivery tube, taking care to keep it facing upright. 

8. Insert the burning splint into the mouth of the test tube. 

Observations

As we added acid into the carbonate, it started creating bubbles in the lime water boiling tube and as we added more acid the lime water turned cloudy and it was a successful experiment.