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3 years ago

5

A chemistry student needs 75.0ml of pentane for an experiment. by consulting the crc handbook of chemistry and physics, the stud

ent discovers that the density of pentane is 0.626·gcm−3 . calculate the mass of pentane the student should weigh out.

1 answer:

vagabundo [1.1K]3 years ago

3 0

Mass=density x volume
0.626 x 75
46.95

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Answer:

Limiting reagent: barium nitrate

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Percent yield: 87%

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Since the reactant react in a 1:1 molar ratio, barium nitrate is the limiting reagent. If all of the limiting reagent reacts, the amount of barium sulfide produced is:

(13.5 mmol Ba(NO₃)₂)(BaS/Ba(NO₃)₂ ) = 13.5 mmol BaS

Converting this amount to grams gives the theoretical yield of BaS (molar mass 169.39 g/mol).

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Now, the number of each element in the unknown compound is determined by the formula:

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n = $\frac{molar mass}{empirical mass}$

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So, the molecular formula is:

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