Decomposition of Calcium Carbonate

The Decomposition of Calcium Carbonate

Error Analysis

Discussion of Theory

In the the experiment we did did prove our hypothesis that the 6 M HCl since it's higher concentrated than the others. We tried to minimize error possibilities by most importantly sticking to the procedure. When we did the experiment we had to make our solutions of HCl, so when we were making them we made sure to get as close to exact measurements by using the ratios needed for using 12 molar HCl. One of the most important things we did to get fully reliable data is that once we poured the hydrochloric acid into the flask with the calcium chloride we put the stopper on the top since that way none of the carbon dioxide gas would escape especially for the 6 molar which reacted faster.

Kinetics: the study of the rates of chemical reactions.

Rate = change in volume / time

It is a first order reaction since our data doubles.

Collision theory

Low concentration = Fewer collisions --> lower rate

Higher concentration = More collisions --> higher rate

6M 30 mL per second

4M 20 mL per second

2M 10 mL per second

1M 05 mL per second

Acid- Base neutralization

CaCO3 is a base, HCl is an acid

Conclusion

While any concentration of will decompose CaCO3s we see in this lab- the concentration that does the most damage in the first 10% of our experimental time is 6M. This has an initial rate of 30 mL of CO2 being produced per second.

By Edwin and Jessalynne

Our NO TECH data

Data for 1 M

Data for 2 M

Data for 4 M

Real life applications

Purpose of this lab

More than 4% of our Earth's crust is composed of calcium carbonate (CaCO3),and then some of the great wonders of our world-The Pyramids and the Taj Mahal are examples- are made of or are in part CaCO3. The problem, however, is the fact that rain can be acidified and then the solubility of the marble and limestone is intensified.

... IN RELATION TO SCIENCE

• Kinetics
• Collision Theory
• Acid-Base Neutralization

Design a kinetics experiment for the heterogenous reaction of CaCO3 with HCl (Acid).

Data for 6 M

Procedure

Using a syringe, a gas pressure sensor and commonly used science equipment-which we all have used- we measured the volume of the gas produced when CaCO3 is exposed to different concentrations of HCl.

Then, we calculated the rate at which our sample was decomposing.

• Dilute the 12M HCl stock solution to your 6M, 4M, 2M, and 1M solutions
• Set up the gas collection apparatus
• Put 0.5 g of CaCO3 (marble chip) into the Erlenmeyer flash.
• Press collect and quickly pour 10 ml of 6M HCl into the flask, and put the stopper in. Time for 10 minutes and stop collection.
• Repeat for 4M, 2M, and 1M

Sample of how we diluted stock solution

Given concentration*volume needed = Desired concentration* volume desired

We want 20mL of 2M HCl solution out of our 12 M stock.

We need 3.3 mL of 12M stock solution and 16.7 mL of H2O

12M * V1 = 2M * 20 mL

12M * V1 = 40 M/ mL

V1 = (40 M/ mL)/ 12 M

V1 = 3.3 mL