Materials 80 mL Carbonated Water 80 mL Acetic Acid (2) Chalk Pieces (CaCO 3 ) Pe
ID: 291060 • Letter: M
Question
Materials
80 mL Carbonated Water
80 mL Acetic Acid
(2) Chalk Pieces (CaCO3)
Permanent Marker
*80 mL Tap Water
*Timer (watch, cell phone, internet, etc.)
Note: You must provide the materials listed in *red.
Labware
(3) 250 mL Beakers
Digital Scale
EXERCISE 1: SPELEOLOGY (UNDERSTANDING CAVE FORMATION)
In this exercise, you will observe what happens to chalk in different solutions and compare your observations to what occurs in nature.
Weathering and Erosion EXERCISE 1 POST-LAB QUESTIONS 1. Do the results of the exercise support your hypothesis? Explain your reasoning. 2. Compare and contrast the reaction of the chalk pieces in each solution 3. Is this exercise an analog for physical or chemical weathering? Explain your reasoning. 4. Using your observations of the chalk in different solutions, explain how a limestone cave formsExplanation / Answer
1. Yes, the reaction of mild acid with calcium carbonate (the chemical from which chalk is composed of) cause leaching (a type of chemical weathering)and due to this leaching the limestone bed get chemically weathered and thus form various caves around the world.
2. When chalk pieces were dissolved in acetic acid then calcium carbonate of chalk reacts with acid to give carbondioxide gas (process is known as effervescence) while when chalk is dissolved in water no chemical reaction takes place and only chalk get dissolved in water.
3. This is an example of chemical weathering as it involves a chemical reaction between chalk and acetic acid given by the reaction:
2 CH3COOH + CaCO3 = H2O + CO2 + Ca(CH3COO)2
4. The chemical reaction between weak acid that is present in acid rain and the limestone will cause chemical weathering and thus give rise to cave formation.