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Lab 3

How Can the Gram Atomic Mass of an Element be Determined?

Unit 3⏱ 90 minGuided Inquiry

Overview

Knowing the atomic mass of one element in a balanced decomposition reaction, how can the gram atomic mass of another element be determined?

Objectives

  • Knowing the atomic mass of one element in a balanced decomposition reaction, how can the gram atomic mass of another element be determined?
  • Connect observations to AP Chemistry models and calculations.
⚠️ Wear protective goggles and an apron. Follow your teacher’s safety directions for all chemicals and equipment.

Materials Needed

Procedure

1

Design a procedure that will determine the molar mass of silver.

2

Assume that you know the molecular formula of silver oxide and the molar mass of oxygen.

3

Start by writing out the balanced decomposition reaction of silver oxide.

4

Write down a detailed step by step procedure.

5

You may use no more than 1.80 grams of silver oxide.

6

Make sure you remove all of the water from your crucible and lid before starting the experiment.

7

Show your proposed procedure to your teacher before attempting the experiment yourself.

8

You may use all of the equipment and chemicals listed above.

9

Note, you may need to reheat your sample to confirm that all of silver oxide has decomposed.

Pre-Lab Questions

1. Answer the objective. Write out the balanced reaction. Include all final numerical calculations, such as gram atomic mass. What was the % error of the experiment? Discuss possible sources of error.

Post-Lab Questions

1. Write a balanced equation for the decomposition of silver oxide. There are two different names for this type of reaction. What are these names and explain why they are called them. Show the redox half reactions for the decomposition of silver oxide. What are the most likely sources or error in this experiment and how might this experiment be improved. Define the terms mole, and gram atomic mass. What other terms are there for gram atomic mass? How many atoms of silver were produced in this experiment based on experimental calculations?