Properties of Acids

3. A further four test tubes were then taken and filled a quarter full with each of the four acids selected and carefully labelled. A piece of magnesium was then added to the first acid in test tube A and any gas given off was collected by placing empty test tube B directly over test tube A. Gas emitted from test tube A is to be collected in test tube B. The gas collected in test tube B was then tested for hydrogen gas by using a lighted taper. Once the lighted taper was added to the gas, it was found that it ignited with "a pop" (the test for hydrogen) and this was noted. This process was then repeated for each acid in turn for magnesium and then again repeated for calcium and zinc with the test for gas made as before and results carefully noted accordingly.

4. The four acids were again selected, poured into test tubes as before carefully labelled and six or seven drops of barium chloride solution were added to the first acid. The effects of adding the drops of barium chloride were then noted to see if the mixture went cloudy and results entered into the results table. This was again repeated for the remaining three acids.

5. The four acids were again selected, poured into test tubes and carefully labelled as before. To each of the 4 acids in the test tubes, a spatula of copper (II) oxide was added in turn to each of the four acids. Each mixture was then gently warmed in turn with the Bunsen burner and this test was true the results were then observed and noted in the results table.

6. Finally, each of the acids were selected, and tested in turn, first with universal indicator solution, then second blue litmus paper. The effects in each case were noted as before.

Variables: Quantitative amounts of each of the four acids, metals and compounds i.e. Sodium Carbonate, Calcium Carbonate, Potassium Carbonate, Magnesium, Calcium, Zinc, Barium Chloride, Copper (II) Oxide, Universal Indicator and Blue Litmus Paper. In addition, the various results were noted.

Controls: Tests for gas and physical and visual changes in the liquids with observations. , , and

RESULTS:

Part 1 - Testing for Carbon dioxide gas:

Note: positive means carbon dioxide gas was detected by the limewater test.

Hydrochloric Acid ()

Sulphuric Acid ()

Ethanoic Acid ()

Nitric Acid ()

Sodium Carbonate

Positive

Positive

Negative

Positive

Calcium Carbonate

Positive

Positive

Positive

Positive

Potassium Carbonate

Positive

Positive

Negative

Positive

Part 2 - Testing for Hydrogen gas:

Note: positive means Hydrogen Gas was detected by the lighted taper test.

Hydrochloric Acid ()

Sulphuric Acid ()

Ethanoic Acid ()

Nitric Acid ()

Magnesium

Positive

Positive

Positive

Positive

Calcium

Positive

Positive

Positive

Positive

Zinc

Positive

Positive

Negative

Negative

Part 3 - Barium Chloride and Copper (II) Oxide:

Acid

Hydrochloric Acid ()

Sulphuric Acid ()

Ethanoic Acid ()

Nitric Acid ()

Barium Chloride

No reaction

Turned White

No reaction

No reaction

Copper (II) Oxide

Solution turns blue

Solution turns blue

Solution turns blue

Solution turns blue

Part 4 - Universal Indicator and Blue Litmus Paper:

Indicator

Hydrochloric Acid ()

Sulphuric Acid ()

Ethanoic Acid ()

Nitric Acid ()

Universal Indicator

Red

Red

Red

Red

Blue Litmus Paper

Pink

Pink

Pink

Pink

EVALUATION:

Overall, sulphuric acid had the strongest reactions and Ethanoic acid had the weakest reactions. This is why no carbon dioxide was produced when the Ethanoic acid reacted with both the sodium carbonate and the potassium carbonate. Generally, Zinc had the weakest reactions out of all the metals. This is why no hydrogen gas was produced with both the nitric acid and the Ethanioc acid.

In part one of the experiment, when testing for carbon dioxide gas, all reactions produced carbon dioxide, except when Ethanoic acid reacted with sodium carbonate and also with potassium carbonate.

In part two of the experiment, only Ethanoic acid and nitric acid did not produce hydrogen gas when the two acids were put with zinc.

In part three of the experiment, Barium Chloride only reacted with Sulphuric acid. Copper (II) oxide, reacted with all four of the acids causing them to turn blue.

Finally, In part four of the experiment, all acids, when mixed with universal indicator turned red and all acids with blue litmus paper turned pink.

A potential source of error would be that when you were testing for the gas, it might have already escaped, which would give you incorrect results. It is extremely important that all labels are clear to ensure the chemicals don't get mixed up and so that you don't have inaccurate results.

CONCLUSION:

For each set of the five compounds, generally similar reactions and results were produced when each of the different acids were mixed with each of the five compounds. In consequence, as discussed, most reactions with carbonates produced carbon dioxide except Ethanoic acid, the reactions with metal usually produced hydrogen and a mixture of acids and copper (II) oxide turned blue when heated. However, when barium chloride was added to the acids only sulphuric acid turned a milky white colour.