1. Distinguish between physical and chemical changes. Include examples in your explanations. 2. What are the differences among elements, compounds and mixtures? 3. Fill in the chart below to identify the properties of shape and volume for each type of matter. 4. Explain how atomic mass and molecular mass are determined. 5. Fill in the chart below to identify and describe the parts of an atom. 6. Identify the assumptions made as part of Dalton’s atomic theory.

consider the reaction below.

 no rx

at 500 k, the reaction is at equilibrium with the following concentrations.

[pci5]= 0.0095 m

[pci3] = 0.020

[ci2] = 0.020 m

what is the equilibrium constant for the given reaction?

0.042

0.42

2.4

24

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.