OSE 7.1 End of Unit Assessment Part 1v (copy)

Explaining Marble Changes in the Taj Mahal

The Taj Mahal was built in Agra, India by the emperor Shah Jahan as a memorial for his wife. It was completed around 1653. It is an impressive building created out of white marble. The Taj Mahal has been named a world heritage site by the United Nations Educational, Scientific, and Cultural Organization. Between 7 and 8 million people visit the Taj Mahal each year. However, in the last 50 years, people have started noticing that the building is turning from white to yellow and the marble is cracking and falling apart.

Plan an Investigation: If you combined a sample of calcium carbonate with any of these substances, how would that provide evidence to support or refute the scientists’ idea that a chemical reaction is occurring between the calcium carbonate and any of them? What evidence would you look for?

We will now investigate some of these substances, starting first with the one of the acids that the algae releases, malic acid.

Plan Your Investigation: Procedure

• Wear goggles throughout this procedure.
• Get the following supplies from your teacher: ~1 g of calcium carbonate, ~20 mL container of water, 1 one capsule of malic acid in a transfer container (e.g. cup), a spoon, a wooden stirrer, and 6 clear cups to transfer samples to and collect observations from.
• You also have access to a digital scale and thermometer.
• In the space provided, make a data table below to record your observations about:
• Each of three substances you have before combining any of them (calcium carbonate, water, and the malic acid).
• What happens when you combine two different substances at a time together.
• What happens when you combine all three substances at a time together.
• Label the clear cups with the different substance(s) you plan to put in each of them.

Write a procedure.

Carry Out Your Investigation: Procedure

• Wear goggles throughout this procedure.
• The malic acid capsule will need to be opened to transfer it into a container. Pull both ends of the capsule apart above an empty container to do this.
• Carry out your investigation recording what you observe before, during, and after 1 minute.
• When you finish, follow the cleanup procedure.
• Wash your hands.

Create a Data Table to collect your data.

Which claim does your data support?

Use the data from your investigation and your key model ideas to support your argument.