1.9: Chemistry, Matter, and Measurement (Exercises)

1. Does each statement refer to a chemical property or a physical property?

   1. Balsa is a very light wood.
   2. If held in a flame, magnesium metal burns in air.
   3. Mercury has a density of 13.6 g/mL.
   4. Human blood is red.

2. Does each statement refer to a chemical property or a physical property?

   1. The elements sodium and chlorine can combine to make table salt.
   2. The metal tungsten does not melt until its temperature exceeds 3,000°C.
   3. The ingestion of ethyl alcohol can lead to disorientation and confusion.
   4. The boiling point of isopropyl alcohol, which is used to sterilize cuts and scrapes, is lower than the boiling point of water.

3. Define element. How does it differ from a compound?

4. Define compound. How does it differ from an element?

5. Give two examples of a heterogeneous mixture.

6. Give two examples of a homogeneous mixture.

7. Identify each substance as an element, a compound, a heterogeneous mixture, or a solution.

   1. xenon, a substance that cannot be broken down into chemically simpler components
   2. blood, a substance composed of several types of cells suspended in a salty solution called plasma
   3. water, a substance composed of hydrogen and oxygen

8. Identify each substance as an element, a compound, a heterogeneous mixture, or a solution.

   1. sugar, a substance composed of carbon, hydrogen, and oxygen
   2. hydrogen, the simplest chemical substance
   3. dirt, a combination of rocks and decaying plant matter

9. Identify each substance as an element, a compound, a heterogeneous mixture, or a solution.

   1. air, primarily a mixture of nitrogen and oxygen
   2. ringer’s lactate, a standard fluid used in medicine that contains salt, potassium, and lactate compounds all dissolved in sterile water
   3. tartaric acid, a substance composed of carbon, hydrogen, and oxygen

10. Identify each material as an element, a compound, a heterogeneous mixture, or a solution.

    1. equal portions of salt and sand placed in a beaker and shaken up
    2. a combination of beeswax dissolved in liquid hexane
    3. hydrogen peroxide, a substance composed of hydrogen and oxygen

11. What word describes each phase change?

    1. solid to liquid
    2. liquid to gas
    3. solid to gas

12. What word describes each phase change?

    1. liquid to solid
    2. gas to liquid
    3. gas to solid

Answers

1.  

   1. physical property
   2. chemical property
   3. physical property
   4. physical property

2.

1. chemical property
2. physical property
3. chemical property
4. physical property

3. An element is a substance that cannot be broken down into chemically simpler components. Compounds can be broken down into simpler substances.

4. A compound is composed of two or more elements combined in a fixed ratio. An element is the simplest chemical substance.

5. a salt and pepper mix and a bowl of cereal (answers will vary)

6. vinegar and rubbing alcohol (answers will vary)

7.  

   1. element
   2. heterogeneous mixture
   3. compound

8.

1. compound
2. element
3. heterogeneous mixture

9.  

   1. solution
   2. solution
   3. compound

10.

1. heterogeneous mixture
2. solution
3. compound

11.

• melting or fusion
• boiling or evaporation
• sublimation

12.

1. freezing
2. condensation
3. deposition