Chapter 1, Problem 1.20E

1.13 Physical properties may change because of a chemical change. For example, the color of an egg white changes from clear to white because of a chemical change when it is cooked. What is another common situation in which a chemical change also leads to a physical change?

How does an element differ from a compound? How are they similar?

Describe how the process offiltrationcould be used to separate a mixture into its components. Give an example.

All molecules attract each other to some extent, and the attraction decreases as the distance between particles increases. Based on this idea, which state of matter would you expect has the strongest inter-actions between particles: solids, liquids, or gases?

Classify the following changes as chemical C or physical P a Baking bread b Grinding sugar into powder c What type of change is represented in c.? d What type of change is represented in d.?

The boiling of water is a physical change because the water disappears. physical change because the gaseous water is chemically the same as the liquid. chemical change because heat is needed for the process to occur. chemical change because hydrogen and oxygen gases are formed from water. chemical and physical change. Explain your answer.

Consider the sample of matter in the illustration below. Answer each question independently and explain your answers. a Is the sample homogenous or heterogeneous? b Is the sample a pure substance or a mixture? c Are the particles elements or compounds? d Is the sample a gas, a liquid, or a solid?

Physical and Chemical Changes Say you are presented with two beakers, beaker A and beaker B, each containing a white, powdery compound. a From your initial observations, you suspect that the two beakers contain the same compound. Describe, in general terms, some experiments in a laboratory that you could do to help prove or disprove that the beakers contain the same compound. b Would it be easier to prove that the compounds are the same or to prove that they are different? Explain your reasoning. c Which of the experiments that you listed above are the most convincing in determining whether the compounds are the same? Justify your answer. d A friend states that the best experiment for determining whether the compounds are the same is to see if they both dissolve in water. He proceeds to take 10.0 g of each compound and places them in separate beakers, each containing 100 mL of water. Both compounds completely dissolve. He then states, Since the same amount of both substances dissolved in the same volume of water, they must both have the same chemical composition. Is he justified in making this claim? Why or why not?

Distinguish precisely and in scientific terms the differences among items in the following groups. a Macroscopic matter, microscopic matter, particulate matter b Physical change, physical property, chemical change, chemical property c Gases, liquids, solids d Element, compound e Atom, molecule f Pure substance, mixture g Homogeneous matter, heterogeneous matter h Reactant, product i Exothermic change, endothermic change j Potential energy, Kinetic energy