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15 Cards in this Set
- Front
- Back
how do you read a burette?
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the final reading minus the initial reading. bottom of the meniscus
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how do you read a graduated cylinder?
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bottom of the meniscus
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how do you use a balance when weighing solids and liquids?
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solids: use a weighing boat and zero it out before adding chemicals to the weigh boat.
liquids: same process but use a weighing bottle |
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how do you transfer chemcials and reagents (solid, liquid, etc)?
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use a pipette
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how do you read a meniscus?
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read from the bottom
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how do you use a volumetric flask to make dilutions?
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add solution(s) and mix back and forth
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how do you calculate standard deviation and mean?
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standard deviation: square root of (x1 - avg x) square + (x2 - avg x) square ..... / (number of x values - 1)
mean: just find the average |
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What different ways can M1V1 = M2V2 be used?
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*dilution is KEY Word*
or if one wants to prepare xmL of a yM solution from a zM solution |
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difference between accuracy and precision?
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accuracy is how close a measurement comes to the actual value of whatever is being measured. precision is concerned with the reproducibility of the measurements.
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what is a mole?
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6.02 x 10^23 molecules or atoms of any given material or substance
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what is molarity?
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molarity is basically the concentration of a substance. it is moles of solute / liters of solution
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what are mole fractions?
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fraction by mole (ratio of moles of solute to total moles of solution) ; moles of solute / moles of solute + moles of water
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how do you calculate percent weight?
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100 x fraction by weight = 100 x weight of solute / weight of solution
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if given a mass of substance, how can you calculate moles?
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divide mass of substance by its molar mass and you get its amount in moles.
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if given moles and volume, how do you find molarity?
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divide number of moles by volume
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