front 1 Purpose of Experiment 2? | back 1 Familiarize w/ the procedures used in evaluating physical properties and the use of these properties to identify substances |
front 2 What will you do in this experiment? | back 2 Use the following properties to identify an unknown substance: solubility, density, melting point, boiling point |
front 3 What are properties? | back 3 the characteristics of a substance that enable us to identify it (distinguish it from all other substances) |
front 4 How can substances be identified? | back 4 some can be identified by simple examination (color, size, shape, texture, odor, etc) others can also quantifiable examination a specif combination of properties is unique to a given substance wh/ makes it possible to ID most by careful examination of their properties |
front 5 What are physical properties? | back 5 can be observed w/o altering the composition of the substance |
front 6 List 5 physical properties: | back 6
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front 7 Give examples of physical properties that are not easily quantifiable | back 7 taste, color, odor, etc (more subjective and difficult to express precisely using numbers) |
front 8 Give examples of physical properties that are more easily quantified. | back 8 Density (g/cm3) Melting point (Celsius), boiling point (C) Viscosity Solubility, Refractive index |
front 9 When water and toluene are mixed, two layers form. Is the bottom layer water or toluene? | back 9 When water and toluene mix, the water will stay on the bottom layer while the toluene floats. This is due to the difference in their density. Since toluene is less dense, it will rise above water and water will remain in the bottom layer. Water density= 1.008 g/mL Toluene density = 0.87 g/mL |
front 10 What is solubility? | back 10 solubility of substance in a solvent (usu water) the maximum weight of that substance that dissolves in a given volume |
front 11 How is solubility expressed (units)? | back 11 g/100 mL |
front 12 What is the formula for density? | back 12 d= m/v |
front 13 What are melting/freezing points? | back 13 the temperature at which the liquid and solid states of a substance are in equilibrium |
front 14 What is the term freezing point? | back 14 the equilibrium temperature when approached from the liquid phase (when the solid begins to appear in the fluid) |
front 15 What is the melting point? | back 15 the equil temp when approached from the solid phase (when liquid begins to appear in the solid) |