How do you calculate the theoretical mass percentage of oxygen in Potassium Chlorate?

The Law of Constant Composition states that all compounds consist of elements in fixed proportions.A percentage by mass is used to express the proportion of elements in a compound.

In Part A of this lab, a sample of potassium chlorate will be analyzed in order to determine the mass percent of oxygen present in it.To do this, the chlorate must be heated to a temperature greater than 400 C.

A quantitative analysis of the reactants and products of this reaction will be performed by students.The law of mass conserves the mass of oxygen released from the original sample.The experimental mass percent of oxygen will be determined from this data.

Mass of Oxygen released andMass of Potassium Chlorate used areexperimental.

Mass percentages of elements in compounds can be calculated using the known chemical formula of the compound.The expression would be used to calculate the theoretical mass percent of oxygen.

Mass Percent of Oxygen is a theoretical figure.

Students can evaluate their accuracy in this experiment by calculating their percent error and comparing their experimental results to the true theoretical value.

The sample left after heating will be qualitatively analyzed in order to demonstrate that it is different from the initial sample.The addition of nitric acid and silver nitrate will be used to test for the presence of chloride ion.A white precipitate is indicative of a positive test.This result will be compared to those obtained for identical tests on known samples of potassium chlorate and potassium chloride to confirm the identity of the residue.

6M nitric acid, 0.1M silver nitrate, and solid potassium chlorate are included.

Handling hot equipment and using the Bunsen burner can be dangerous.Most items look the same whether they are hot or cold.The sample should be heat slowly to avoid splattering.Silver nitrate can stain the skin and nitric acid can burn it.If there is a spill of either chemical, rinse under the water and report it to your instructor.The sinks may have a solution for Nitric acid spills.

Your data can be used to determine the experimental mass percent of oxygen.You can clearly see your work in the table below.

The theoretical mass percent of oxygen in (ceKClO3) can be calculated using the known formula of potassium chlorate.You should show your work clearly.

The percent error between your average experimental value and theoretical value is called the mass percent of oxygen.You should show your work clearly.

Explain how your observations in the table confirm the presence of potassium chloride.