Chem 151 Exam 1 with precise detailed solutions

Chem 151 Exam 1 with precise |! |! |! |! |!




detailed solutions
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What are chemists' three central goals and what kind of questions should be asked? -
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Correct answer ✔Analysis- What is this?
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Synthesis- How do I make it? |! |! |! |! |!




Modeling- How do I explain it? |! |! |! |! |!




intensive property - Correct answer ✔DO NOT depend on the amount of material
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Melting point, boiling point, density, color
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CHARACTERISTIC |!




of a material
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extensive property - Correct answer ✔Depend on the amount of material
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Length, Mass, Area |! |! |!




Independent of the type or identity of the material |! |! |! |! |! |! |! |! |!




Tell you HOW MUCH
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quantitative - Correct answer ✔any value recorded directly from a tool is considered
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quantitative data (numbers based) |! |! |!




qualitative - Correct answer ✔It includes such descriptions as color as well as observations
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about texture changes and anything else that is actually an opinion (try describing the
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difference in color between two different blades of grass)
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significant figures rules - Correct answer ✔1. Zeroes in the beginning of a number never
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count.

, 2. Zeroes at the end of a number count only if there is a written decimal point.
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3. The digits 1 - 9 always count.
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4. Zeroes between the digits 1 - 9 always count.
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matter - Correct answer ✔anything that has mass and occupies space
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substance - Correct answer ✔that object which has mass and occupies space
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composition - Correct answer ✔the makeup of something (components)
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state - Correct answer ✔its physical form/condition
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three states of matter - Correct answer ✔gas, liquid, solid
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solid - Correct answer ✔-atoms or molecules pack close to each other in fixed locations
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-vibrate but do not move around or past each other
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-fixed volume and shape
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crystalline - Correct answer ✔case in solid state where atoms or molecules are in patterns
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with long-range, repeating order ex) salt and diamond
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amorphous - Correct answer ✔case where a solid's atoms or molecules do not have any
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long-range order. ex.) glass and plastic |! |! |! |! |!




liquid - Correct answer ✔atoms or molecules pack about as closely as they do in solid
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matter however they are free to move relative to each other, giving liquids a fixed
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volume but not a fixed shape.
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