Chemistry, 21.01.2020 20:31 xatziry1717

At a certain temperature the vapor pressure of pure heptane is measured to be . suppose a solution is prepared by mixing of heptane and of acetyl bromide .

Answers: 3

Show answers

Answers

Answer from: jaylon78

This is an incomplete question, here is a complete question.

At a certain temperature the vapor pressure of pure heptane is measured to be 170 torr. Suppose a solution is prepared by mixing 86.7 g of heptane and 125 g of acetyl bromide.

Calculate the partial pressure of heptane above this solution. Round your answer to 3 significant digits.

Answer : The partial pressure of heptane is, 78.2 torr

Explanation : Given,

Mass of heptane = 86.7 g

Mass of acetyl bromide = 125 g

Molar mass of heptane = 100 g/mole

Molar mass of acetyl bromide = 122.9 g/mole

First we have to calculate the moles of heptane and acetyl bromide.

$\text{Moles of heptane}=\frac{\text{Mass of heptane}}{\text{Molar mass of heptane}}=\frac{86.7g}{100g/mole}=0.867mole$

and

$\text{Moles of acetyl bromide}=\frac{\text{Mass of acetyl bromide}}{\text{Molar mass of acetyl bromide}}=\frac{125g}{122.9g/mole}=1.017mole$

Now we have to calculate the mole fraction of heptane and acetyl bromide.

$\text{Mole fraction of heptane}=\frac{\text{Moles of heptane}}{\text{Moles of heptane}+\text{Moles of acetyl bromide}}=\frac{0.867}{0.867+1.017}=0.460$

and

$\text{Mole fraction of acetyl bromide}=\frac{\text{Moles of acetyl bromide}}{\text{Moles of heptane}+\text{Moles of acetyl bromide}}=\frac{1.017}{0.867+1.017}=0.539$

Now we have to partial pressure of heptane.

$p_{heptane}=X_{heptane}\times p^o_{heptane}$

where,

$p^o_{heptane}$ = partial pressure of heptane

$p_{heptane}$ = total pressure of gas

$X_{heptane}$ = mole fraction of heptane

$p_{heptane}=X_{heptane}\times p^o_{heptane}$

$p_{heptane}=0.460\times 170torr=78.2torr$

Therefore, the partial pressure of heptane is, 78.2 torr

Answer from: Quest

- calcium has greater affinity to bond with electron receptors than hydrogen does and hence, it has the ability to replace hydrogen in most of its compounds.

- lithium has 2 valence electrons in the product because it can make only 1 bond with hydrogen. beryllium has 4 valence electrons in the product because it can only make 2 bonds. it has fewer electrons than neon and can react with electron donors. each hydrogen has 2 valence electrons, the same as helium.

- the covalent bond formed between carbon and hydrogen is polar because carbon is more electronegative than hydrogen and it attracts the bonded electron pair closer to itself, thus giving hydrogen a partial positive charge.

- a hydrogen bond is a relatively weak bond that hydrogen atoms make with the electronegative atoms nitrogen, oxygen or fluorine.

so the best choice is a.) 2 calcium (ca) atoms

Answer from: Quest

we can conclude that the melting point of table salt is above room temperature (it's actually 801 deg c). the melting point of mercury must be below room temperature (- 39 deg c).