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4 years ago

Phenol is a compound that contains 76.57% carbon, 6.43% hydrogen, and 17.0% oxygen. Calculate the empirical formula.

Chemistry

1 answer:

Ulleksa [173]4 years ago

3 0

Answer:

C₆H₆O

Explanation:

The given values are the percentage in mass of each element. Empirical formula is the simplest ratio of atoms presents in a molecule. Thus, the first we need to do is convert this percentage to mass using molar mass of each element:

Moles C:

76.57C * (1mol / 12g) = 6.38 moles C

Moles H:

6.43 * (1mol / 1g) = 6.43 moles H

Moles O:

17.0% * (1mol / 16g) = 1.06 moles O

Dividing each number of moles in the moles of O (The minimum number of moles. Used to obtain "The simplest ratio..."):

C = 6.38 moles C / 1.06 moles O = 6

H = 6.43 moles H / 1.06 moles O = 6

O = 1.06 moles O / 1.06 moles O = 1

That means empirical formula of phenol is:

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A sample of a compound contains 3.21 g of sulfur and 11.4 g of fluorine. Which of the following represents the empirical formula

Sergeeva-Olga [200]

Answer:

The empirical formula is SF6 (option E)

Explanation:

Step 1: Data given

Mass of sulfur = 3.21 grams

Mass of fluorine = 11.4 grams

Molar mass sulfur = 32.065 g/mol

Molar mass fluorine = 19.00 g/mol

Step 2: Calculate moles

Moles = mass /molar mass

Moles sulfur = 3.21 grams / 32.065 g/mol

Moles sulfur = 0.100 moles

Moles fluorine = 11.4 grams / 19.00 g/mol

Moles fluorine = 0.600 moles

Step 3: Calculate mol ratio

We divide by the smallest amount of moles

S: 0.100 / 0.100 = 1

F : 0.600 / 0.100 = 6

The empirical formula is SF6 (option E)

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3 years ago

Calculate the vapor pressure in torr of a solution containng 24.5 g of glycerin (C3H8O3) in 135 mL water at 30.0* C; the vapor p

Otrada [13]

Psolution = X · PH_20
= 0.966 · 31.8 torr
= 30.7 torr

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2 years ago

What is the term for a type of reaction in which an acid and a base react to produce a salt and water?

WINSTONCH [101]

Neutralization
is the probable answer, which I don't know how to explain, but I know that's the answer because I learned about it a few years ago and I'm pretty smart. =]

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3 years ago

he heat of fusion of tetrahydrofuran is . Calculate the change in entropy when of tetrahydrofuran melts at . Be sure your answer

lana [24]

Answer:

$\Delta S=1.8x10^{-3}\frac{kJ}{K}=1.8\frac{J}{K}$

Explanation:

Hello.

In this case, given the heat of fusion of THF to be 8.5 kJ/mol and freezing at -108.5 °C, for the required mass of 5.9 g, we can compute the entropy as:

$\Delta S=\frac{n*\Delta H}{T}$

Whereas n accounts for the moles which are computed below:

$n=5.9g*\frac{1mol}{72g} =0.082mol$

Thus, the entropy turns out:

$\Delta S=\frac{0.0819mol*8.5 kJ/mol}{(-108.5+273.15)K}\\\\\Delta S=1.8x10^{-3}\frac{kJ}{K}=1.8\frac{J}{K}$

Best regards.

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The Percentage of salt-water vs. fresh-water:???%

I am Lyosha [343]

Answer:

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