Name __________________ Date ___________________ Period: ______
A. Read the passage below:
You have probably used a piece of chalk to write on the blackboard or a sidewalk. Natural chalk is primarily composed of calcium carbonate (CaCO3), the same ingredient that composes the shell of many marine organisms such as clams and oysters. Modern chalk is mainly composed of gypsum (CaSO4) and may contain trace amounts of calcium carbonate (CaCO3). In this demonstration, you will observe the effect of varying pH on the chalk.
1. What chemical can be found in both chalk and oyster shells? __CaCO3___________________
B. Chalk Demonstration
Complete the table below as your teacher performs the demo