key-eng-fall07-q8059x01b2w

key-eng-fall07-q8059x01b2w - Identify two properties from...

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CHEM 2045C: Quiz 1 NAME ______KEY_________________ N #_______________ Show your work for full credit Eng Q8059x01-beta-2-w NOTE: for multiple choice answers, there may be more than one answer. 1. (2 pts) Classify each of the following as a pure substance or a mixture. IF a mixture, indicate whether it is homogeneous or heterogeneous: [a] iron pure substance [b] vomit heterogeneous mixture 2. (2 pts) In the process of attempting to characterize a substance, a chemist makes the following observations: The substance is a silver white, lustrous metal. It melts at 649 °C and boils at 1105 °C. Its density at 20 °C is 1.738 g/cm 3 . The substance burns air, producing white light. It reacts with chlorine to give a brittle white solid. The substance can be pounded into thin sheets or drawn into wires. It is a good conductor of electricity.
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Unformatted text preview: Identify two properties from above: one physical and one chemical. Physical (many possibilities): white, melts at 649 C, has a density of 1.738 g/cm 3 , good conductor, etc. Chemical (two possibilities): burns air and reacts with chlorine. 3. (3 pts) Which of the following are NOT SI base units? [a] second [e] meter [b] mole [f] gram (its kilogram) [c] liter (derived unit) [g] Celsius (its Kelvin) [d] kilogram [h] Kelvin 4. (3 pts) Give the number of significant figures for each number. [a] 1.3004 10 2 dg [b] 4.0 cL [c] 0.0003024 km 5 sig figs 2 sig figs 4 sig figs 5. (4 pts) One hundred centigrams (cg) equal one gram (g). Ten decigrams (dg) equal one gram (g). How many dg are in 0.421 cg? 0421 1 100 10 1 0 0421 . . cg g cg dg g dg = 6. (1 pt) What element has the chemical symbol H? Hydrogen...
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