Question

substances vs. mixtures
a substance is matter for which a chemical formula can be written. elements and compounds are substances. mixtures are combinations of two or more substances in which the parts are not chemically bonded.
classify the following as either a substance (s) or a mixture (m).

1. ______ sodium
2. ______ water
3. ______ soil
4. ______ coffee
5. ______ oxygen
6. ______ alcohol
7. ______ carbon dioxide
8. ______ cake batter
9. ______ pure air
10. ______ soup
11. ______ iron
12. ______ salt water
13. ______ ice cream
14. ______ nitrogen
15. ______ eggs
16. ______ blood
17. ______ table salt
18. ______ nail polish
19. ______ milk
20. ______ coca - cola®

Explanation:

Classify each item as a substance (S, has a defined chemical formula, element or compound) or mixture (M, combination of unbonded substances):

1. Sodium is an element (has formula Na).
2. Water is a compound (formula H₂O).
3. Soil is a mix of minerals, organic matter, etc.
4. Coffee is a mix of water, coffee solids, etc.
5. Oxygen is an element (formula O₂).
6. Alcohol (ethanol) is a compound (formula C₂H₅OH).
7. Carbon dioxide is a compound (formula CO₂).
8. Cake batter is a mix of flour, eggs, milk, etc.
9. Pure air is a mix of nitrogen, oxygen, etc.
10. Soup is a mix of water, vegetables, etc.
11. Iron is an element (formula Fe).
12. Salt water is a mix of NaCl and H₂O.
13. Ice cream is a mix of cream, sugar, etc.
14. Nitrogen is an element (formula N₂).
15. Eggs are a mix of proteins, fats, water, etc.
16. Blood is a mix of cells, plasma, etc.
17. Table salt (NaCl) is a compound.
18. Nail polish is a mix of solvents, pigments, etc.
19. Milk is a mix of water, fats, proteins, etc.
20. Coca-cola is a mix of water, sugar, flavorings, etc.

Answer:

1. S sodium
2. S water
3. M soil
4. M coffee
5. S oxygen
6. S alcohol
7. S carbon dioxide
8. M cake batter
9. M pure air
10. M soup
11. S iron
12. M salt water
13. M ice cream
14. S nitrogen
15. M eggs
16. M blood
17. S table salt
18. M nail polish
19. M milk
20. M Coca-cola®