Chapter 1, Problem 1.17E

a Which of the following substances would you expect to be elements and which would you expect to be compounds? 1 calcium carbonate; 2 arsenic; 3 uranium; 4 potassium chloride; 5 chloromethane. b On what general rule do you base your answers to part a? Can you name any exceptions to this general rule?

If we classify substances as ionic, molecular, macromolecular, or metallic, in which if any categories are all the members a. soluble in water? b. electrical conductors in the melt? c. insoluble in all common solvents? d. solids at room temperature?

All of the following processes involve a separation of either a mixture into substances or a compound into elements. For each, decide whether a physical process or a chemical reaction is required. a Sodium metal is obtained from the substance sodium chloride. b Iron filings are separated from sand by using a magnet. c Sugar crystals are separated from a sugar syrup by evaporation of water. d Fine crystals of silver chloride are separated from a suspension of the crystals in water. e Copper is produced when zinc metal is placed in a solution of copper(II) sulfate, a compound.

Consider two boxes with the following contents: the first box contains 10 blue paper clips and 10 red paper clips; the second contains the same number of each color of paper clip with the difference that each blue paper clip is interlocked with a red paper clip. Which box has contents that would be an analogy for a mixture, and which box has contents that would be an analogy for a compound?

From the information given, classify each of the pure substances A through D as elements or compounds, or indicate that no such classification is possible because of insufficient information. a. Substance A cannot be broken down into simpler substances by chemical means. b. Substance B cannot be broken down into simpler substances by physical means. c. Substance C readily dissolves in water. d. Substance D readily reacts with the element chlorine.

A material is believed to be a compound. Suppose you have several samples of this material obtained from various places around the world. Comment on what you would expect to find upon observing the melting point and color for each sample. What would you expect to find upon determining the elemental composition for each sample?

Classify each of the following properties of the metal magnesium as a physical property or a chemical property. a. Solid at room temperature b. Ignites upon heating in air c. Hydrogen gas is produced when it is dissolved in acids d. Has a density of 1.738 g/cm3 at 20C

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

Make molecular-level (microscopic) drawings for each of the following. a. Show the differences between a gaseous mixture that is a homogeneous mixture of two different compounds, and a gaseous mixture that is a homogeneous mixture of a compound and an element. b. Show the differences among a gaseous element, a liquid element, and a solid element.