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3 years ago

15

A student is trying to identify a clear liquid that he finds in a beaker in the classroom. He thinks the liquid might be either

water or ethanol, and he decides to identify the liquid using a density. The density of water is 1 g/cm3. The density of ethanol (clear alcohol) is 0.789 g/cm3.
The student has 50 cm3 of the liquid, and its mass is 4.99 grams. What is the identity of the liquid?

A. ethanol
B. water
C. neither water nor ethanol
D. a 50/50 mixture of water and ethanol

PLEASE BE RIGHT, WORTH 30 PTS !!!, REPLY FAST !!

1 answer:

kumpel [21]3 years ago

3 0

Simply mulitply the volume by the density. As we shall see, this is dimensionally consistent.

Explanation:

density

ρ

=

Mass

Volume

, and thus units of

g

⋅

m

L

−

1

are reasonable.

For this problem:

17.4

⋅

m

L

×

0.798

⋅

g

⋅

m

L

−

1

≅

14

⋅

g

but A i supposed?

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Now we have to calculate the enthalpy of neutralization.

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where,

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$\Delta H=\frac{-4480.96J}{0.08mole}=-56012J/mole=-56.012kJ/mol$

The negative sign indicate the heat released during the reaction.

Therefore, the enthalpy of neutralization is, 56.012 kJ/mole

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