Chapter 1, Problem 1.18E

Which of (he following are true? P4 is considered a compound. Metal rusting on a car is a chemical change. Dissolving sugar in water is a chemical change. Sodium chloride (NaCl) is a homogeneous mixture.

Seawater is composed of salt, sand, and water. Is seawatera heterogeneous or homogeneous mixture? Explain.

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?

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

Questions 47 and 48: Samples of matter may be classified in several ways, including gas, liquid, or solid G, L, S; pure substance or mixture P, M; homogenous or heterogeneous Hom, Het; and, for pure substances, element or compound E, C. For each substance in the left column of the tables shown, place in the other columns the symbol from the top of the column that best describes the substance in its most common state at room temperature and pressure. Assume that the material is clean and uncontaminated. The first box is filled in as an example. G, L, S P, M Hom, Het E, C Factory smokestack emissions All, but mostly G Concrete in a sidewalk Helium Hummingbird feeder solution Table salt

Questions 47 and 48: Samples of matter may be classified in several ways, including gas, liquid, or solid G, L, S; pure substance or mixture P, M; homogenous or heterogeneous Hom, Het; and, for pure substances, element or compound E, C. For each substance in the left column of the tables shown, place in the other columns the symbol from the top of the column that best describes the substance in its most common state at room temperature and pressure. Assume that the material is clean and uncontaminated. The first box is filled in as an example. G, L, S P, M Hom, Het E, C Limestone calcium carbonate Lead Freshly squeezed orange juice Oxygen Butter in the refrigerator

From the information given in the following equations, classify each of the pure substances A through G as elements or compounds, or indicate that no such classification is possible because of insufficient information. a. A B + C b. D + E F + G

Describe how a homogeneous mixture differs from a heterogeneous mixture.

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