The purpose of this experiment is to discover the reaction rate in which acid rain weathers marble statues, or in our case, marble chips.
Marble is especially sensitive to the degrading by acidic chemicals, also to weathering. Acid rain is one of the top degradation agents for marble artefacts around the world. Acid rain contains carbonic acid, nitric acid and sulphuric acid (CO2, NO2, and SO2). The chemical equation that is going to be followed throughout the experiment will be:
CaCO3(s) + 2HCl(aq) –> CaCl2(aq) + H2O(l) + CO2(g)
Multiple factors can impact on the rate of the reaction between the acidic factors and the marble particles. These are stated below;
- Particle size of the marble and the acid
- Temperature of the climate around the statue.
Questions and Hypotheses
The higher the concentration of hydrochloric acid in the beaker, the faster the reaction will take place. This is because there will be more hydrochloric acid particles to collide with the marble chip particles. Therefore resulting in a quicker reaction. The lower the concentration, the weaker the reaction will be as there will be fewer particles, so there will be less chance of the marble reacting.
- Safety goggles
- Hair tied back
- Appropriate footwear
- All chairs tucked under benches
- Approval from teacher before carrying out your experiment
- 4g of marble chips
- 24 ml of hydrochloric acid
- 30 ml of diluted water
- A spatula for the marble chips
- Scientific weighing scales
- 4x test tubes
- 1x 10ml measuring cylinder
(The results that are collected will need to be recorded, a table will be necessary for this.)
- Set up test tube next to each other in visible site
- Numbered each test tube with #1, #2, #3, and #4 written on the tape.
- Plugged in scientific scales and weighed out 1g of marble chips for each test tube.
- Marble chips placed onto pieces of paper.
- Measured 5ml of hydrochloric acid in the 10ml measuring cylinders and placed into each beaker separately.
- Measured out 1ml of water in a 10ml measuring cylinder and placed into the test tube labelled #2.
- Measured out 2ml of diluted water in a 100ml measuring cylinder and placed into the test tube with the label #3.
- Measured out 3ml of diluted water in a 100ml measuring cylinder, and placed into the test tube with the label #4.
- Referred to the table that was drawn before starting the experiment.
- Prepared the stop watch to record how long it took for the marble chips to dissolve.
- Used the pieces of paper to put the marble chips into the test tubes #1, #2, #3, #4
- Started the timer and recorded the time it took for the marble chips to dissolve.
|Concentrated (test tube #1)||22 minutes and 24 seconds||Hydrochloric acid went white and was fizzing; the test tube had gathered around 4 cm of condensation.|
|Diluted (1ml) (test tube #2)||24 minutes and 18 seconds||Diluted hydrochloric acid (1ml) went white and was fizzing; the test tube had gathered around 6 cm of condensation.|
|Diluted (2ml) (test tube #3)||25 minutes and 37 seconds||Diluted hydrochloric acid (2ml) went white and was fizzing; the test tube had gathered around 7 cm of condensation.|
|Diluted (3ml) (test tube #4)||27 minutes and 9 seconds.||Diluted hydrochloric acid (3ml) went white and was fizzing; the test tube had gathered around 8 cm of condensation.|