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Chemistry OYO
Module 4 - OYO
Question | Answer |
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4.1 Classify the following as elements, compounds, homogeneous mixtures, or heterogeneous mixtures: a. copper b. carbon dioxide c. cake icing d. tomato e. sugar water f. sodium g. fruitcake h. sodium fluoride i. tap water | a. Element b. Compound c. Homogeneous d. Heterogeneous e. Homogeneous f. Element g. Heterogeneous h. Compound i. Homogeneous |
4.2 Classify the following changes as physical or chemical: a. Stream condenses into water. b. Gasoline burns in an automobile engine. c. A barber cuts your hair. d. Milk sours. e. Sugar dissolved in water. f. Milk poured on cereal. g. An iron nail rusts. | a. Physical b. Chemical c. Physical d. Chemical f. Physical g. Chemical |
4.3 Cubes of frozen alcohol are put into liquid alcohol. Will the cubes float or sink? | Sink. |
4.4 Natural gas companies store most of their natural gas in liquid form rather than in its gas phase, even though they must deliver it to their customers as a gas. Why do they do this? | The liquid form does not take as much space as the gas form. |
4.5 If a substance is cooled down 10 degrees, will its molecules be moving faster or slower? Will the molecules be closer together or farther apart? | Slower. Closer together. |
4.6 Determine whether the first non-example equation on page 122 is balanced. | It is balanced. |
4.7 Determine whether the second non-example equation on page 122 is balanced. | It is not balanced. |
4.8 Hydrogen and oxygen can react together violently to make water. Write a balanced chemical equation for this reaction. | 2H₂ + O₂ → 2H₂O |
4.9 Solid calcium carbonate (CaCO₃) is made when solid calcium reacts with gaseous oxygen and solid carbon. What is the balanced chemical equation for this reaction? | 2Ca + 2C + 3O₂ → 2CaCO₃ |
4.10 Balance the non-example equation on page 125. | C₅H₁₂(l) + 8O₂(g) → 5CO₂(g) + 6H₂O(g) |