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saveliy_v [14]
3 years ago
10

Determine whether each melting point observation corresponds to a pure sample of a single compound or to an impure sample with m

ultiple compounds.
Chemistry
1 answer:
daser333 [38]3 years ago
4 0

The question is incomplete, the complete question is;

Determine whether each melting point observation corresponds to a pure sample of a single compound or to an impure sample with multiple compounds.

Experimental melting point is BELOW literature value

Experimental melting point is CLOSE to literature value

WIDE melting point range

NARROW melting point range

Answer:

narrow melting point-pure sample of a single compound

experimental melting point is close to literature value-pure sample of a single compound

wide melting point range-impure sample of multiple compounds

experimental melting point is below literature value-impure sample of multiple compounds

Explanation:

The experimental melting point of a pure single compound is sharp and extremely close to the melting point of the substance as recorded in the literature. Usually, a pure substance melts within a narrow range of temperatures.

Impure samples of multiple compounds melt over a range of temperatures. Also if the experimental melting point is well below the record in literature, then the sample is contaminated by other compounds.

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CaCO3(s)→CaO(s)+CO2(g)2                           POSITIVE

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Explanation:

We have to remember, to solve this problem, that the entropy of a gas is higher than that of a liquid which in turn  is higher than the solid. Therefore, comparing the reactants and products look for changes in the state of reactants and products. We also have to look for the increase or decrease of moles of each state based on the balanced chemical reaction.

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I2(s)→I2(g)

1 mol solid I₂ goes into 1 mol gas making the change in  the entropy higher.

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