Planning and Designing Chemistry Lab- To investigate the rate of reaction when calcium carbonate powder and lumps reacts with an acid
You are provided with calcium carbonate in the form of lumps and as a powdered substance, both dilute hydrochloric acid and sulphuric acid are available to you. Plan and design an investigation that you would carry out to compare the rate of reactions of both forms of calcium carbonate with an acid
Hypothesis: Powdered calcium carbonate will react faster with an acid than calcium carbonate lumps
To investigate the rate of reaction when calcium carbonate powder and lumps reacts with an acid.
thistle funnel, tap, gas syringe, flask, hydrochloric acid, sulphuric acid, calcium carbonate (lumps and powder) stop-watch,
- Set up apparatus as shown in diagram below
- Measure 10g of CaCO3 lumps and add it to the flask. Add 50cm3 of HCl to the flask. Record the volume of gas produced every 30sec
- Repeat this step for the powdered CaCO3
Please Note: HCl was used in preference to the H2SO4 as, CaCO3 when mixed with H2SO4 forms a slightly soluble salt and thus the reaction will end quickly.
- Controlled – volume of acid, concentration of acid, and mass of CaCO3 lumps and powder
- Manipulated: sample of CaCO3 lumps and CaCO3 powder
- Responding – volume of gas produced
Interpretation of Results:
The graph shows how much CO2 gas evolved from the experiment. The difference in shapes is because the powder caused the reaction to go at a faster rate than the lumps. The reactions finished at the same time because the masses were the same.
If at the end of the experiment the CaCO3 powder will react at a faster rate than the CaCO3 lumps then the hypothesis would be acceptable.
Sources of Error / Limitations:
Some of the gas escaped whilst being measured this skewing the results.
Assumption: Calcium carbonate reacts faster in the powdered form.