Practice Problems

Concepts

1. Classify each of the following as element, compound, or mixture.

    a) alunminum

    b) table salt

    c) milk

    d) ethyl alcohol

2. Write the symbols for the following elements.

    a) Krypton

    b) Iron

    c) Gold

    d) Rubidium

3. Write the symbols for the folliwing elements.

    a) Silicon

    b) Lithium

    c) Barium

    d) Mercury

4. How would you separate the following into its different components?

    a) a mixture of gases?

    b) a solution of alcohol and water?

    c) a mixture of aluminum powder and alcohol?

Answers

1. a) element

   b) compound

   c) mixture

   d) compound

2. a) Kr

   b) Fe

   c) Ag

   d) Rb

3. a) Si

   b) Li

   c) Ba

4. a) gas-liquid chromatography

   b) gas-liquid chromatography

   c) distillation

Measurements

* Calculater, paper, and a writing utencil might be useful.

1. Write the appropriate symbol in the blank.(>,<,=)

    a) 606 mm     6.06 m

    b) .078 km     .00078 cm

    c) .04 dm     4 mm

2. The temperature of a boiling pot of water is 105.2^oC. What is that temperature in fahrenheit? Kelvin?

3. Rubidium's melting point is 39^oC. If Rubidium were left in a car on a sunny day that had an inside temperature of 311K, would it melt?

Answers

1. a) <

   b) >

   c) =

2. F = 1.8(105.2) + 32

   F = 222.44^oF

   K = 105.2 + 273.15

   K = 378.35K

3. First, convert 311k to degrees celcius.

    311 = ^oC + 273.15
    ^oC = 37.85

   Since the melting point of Rubidium is 39^oC, it does not melt.