Ask question

Ask question

All categories

3 years ago

5

Heptane (C7H16) and octane (C8H18) are constitutents of gasoline. At 80 degree celsius, the vapor pressure of heptane is 428mmHg

and the vapor pressure of octane is 175mmHg. What Xheptane in a mixture of heptane and octane that has a vapor pressure of 305mmHg and 80 degree celsius?

2 answers:

harkovskaia [24]3 years ago

7 0

<u>Answer:</u> The mole fraction of heptane at 80°C is 0.506

<u>Explanation:</u>

We are given:

Vapor pressure of heptane at 80°C = 428 mmHg

Vapor pressure of octane at 80°C = 175 mmHg

Total pressure at 80°C = (428 + 175) = 603 mmHg

To calculate the mole fraction of heptane at 80°C, we use the equation given by Raoult's law, which is:

$p_{heptane}=p_T\times \chi_{heptane}$

where,

$p_A$ = partial pressure of heptane = 305 mmHg

$p_T$ = total pressure = 603 mmHg

$\chi_A$ = mole fraction of heptane = ?

Putting values in above equation, we get:

$305mmHg=603mmHg\times \chi_{heptane}\\\\\chi_{heptane}=0.506$

Hence, the mole fraction of heptane at 80°C is 0.506

ss7ja [257]3 years ago

4 0

Looking at this equation P= (pa*pb)/ (pa+(pb-pa)) ya where pa=vap press a and ya= vap composition a and P= total pressure,it relates vapor pressure mixture to vapor composition. This is derived using the combination of Dalton's and Raoult's laws.

You might be interested in

A high jumper jumps 2.09m. If the jumper has a mass of 72kg, what is his gravitational potential energy at the highest point of

Furkat [3]

Si Ko alam hehehehe sorrry men

4 0

3 years ago

Determine the electron-group arrangement, molecular shape, and ideal bond angle(s) for each of the following:

Alja [10]

The electron-group arrangement of CO₃²⁻ is trigonal planar. The molecular shape is trigonal planar, and the ideal bond angle(s) is CO₃²⁻ is 120°

<h3>What is the molecular geometry of a compound?</h3>

The position of the compound's electrons and nuclei can be seen in the molecular geometry. It demonstrates how the form of the complex is created by the interaction of electrons and nuclei.

Here, according to the VSEPR theory, the shape of the carbonate ion is trigonal planar. The carbon will be in the center.

Thus, the electron-group arrangement and the shape of the carbonate ion are trigonal planar. The bond angle will be 120°.

To learn more about molecular geometry, refer to the link:

brainly.com/question/16178099

#SPJ4

6 0

1 year ago

A solution is made by adding 50.0 ml of 0.200 m acetic acid (ka = 1.8 x 10–5) to 50.0 ml of 1.00 x 10–3m hcl. (a) calculate the

Irina18 [472]

Answer:

Final pH of the solution: 2.79.

Explanation:

What's in the solution after mixing?

$\displaystyle c = \frac{n}{V}$ ,

where

$c$ is the concentration of the solute,

$n$ is the number of moles of the solute, and

$V$ is the volume of the solution.

$V(\text{Final}) = 0.050 \;\textbf{L} + 0.050\;\textbf{L} = 0.100\;\textbf{L}$ .

Acetic (ethanoic) acid:

$\displaystyle \begin{aligned}n &= c(\text{Before})\cdot V(\text{Before}) \\&= 0.050\;\text{L} \times 0.200\;\text{mol}\cdot\text{L}^{-1}\\ &= 0.0100\;\text{mol}\end{aligned}$ .

$\displaystyle \begin{aligned}c(\text{After}) &= \frac{n}{V(\text{After})}\\ &= \frac{0.0100\;\text{mol}}{0.100\;\text{L}}\\ &= 0.100\;\text{mol}\cdot\textbf{L}^{-1}\\ &= 0.100\;\text{M}\end{aligned}$ .

Hydrochloric acid HCl:

$\begin{aligned}n &= c(\text{Before})\cdot V(\text{Before})\\ &= 0.050\;\text{L} \times 1.00\times 10^{-3}\;\text{mol}\cdot\text{L}^{-1}\\ &= 5.00\times 10^{-5}\;\text{mol}\end{aligned}$ .

$\displaystyle \begin{aligned}c(\text{After}) &= \frac{n}{V(\text{After})}\\ &= \frac{5.00\times 10^{-5}\;\text{mol}}{0.100\;\text{L}}\\ &= 5.00\times 10^{-4}\;\text{mol}\cdot\textbf{L}^{-1}\\ &= 5.00\times 10^{-4}\;\text{M}\end{aligned}$ .

HCl is a strong acid. It will completely dissociate in water to produce H⁺. The H⁺ concentration in the solution before acetic acid dissociates shall also be $5.00\times 10^{-4}\;\text{M}$ .

The Ka value of acetic acid is considerably small. Acetic acid is a weak acid and will dissociate only partially when dissolved. Construct a RICE table to predict the portion of acetic acid that will dissociate. Let the change in acetic acid concentration be $-x\;\text{M}$ . $x > 0$ .

$\begin{array}{c|ccccc}\textbf{R}&\text{CH}_3\text{COOH}\;(aq) &\rightleftharpoons &\text{CH}_3\text{COO}^{-}\;(aq) &+& \text{H}^{+}\;(aq)\\\textbf{I}&0.100\;\text{M} & & & & 5.00\times 10^{-4}\;\text{M}\\\textbf{C}&-x\;\text{M} & & +x\;\text{M} & & +x\;\text{M} \\ \textbf{E}&0.100\;\text{M}-x\;\text{M} & & x\;\text{M} & & 5.00\times 10^{-4}\;\text{M} + x\;\text{M}\end{array}$ .

$\displaystyle K_a = \frac{[\text{CH}_3\text{COO}^{-}\;(aq)]\cdot[\text{H}^{+}\;(aq)]}{[\text{CH}_3\text{COOH}\;(aq)]} = \frac{x\cdot(x + 5.00\times 10^{-4})}{0.100 - x}$ .

Rewrite as a quadratic equation and solve for $x$ :

$x\cdot(x + 5.00\times 10^{-4}) = (1.8\times 10^{-5} )\cdot (0.100 - x)$

$x\approx 0.00111$ .

The pH of a solution depends on its H⁺ concentration.

At equilibrium

$[\text{H}^{+}\;(aq)] = 5.00\times 10^{-4}\;\text{M} + x\;\text{M} = 0.00161\;\text{M}$ .

$\text{pH} = -\log{[\text{H}^{+}]} = 2.79$ .

5 0

3 years ago

Which force is a contact force

stiks02 [169]

Answer:

B. a bike braking

Explanation:

It involves friction! Hope this helps!

8 0

3 years ago

Read 2 more answers

Briefly explain the meaning of the following term forward reaction

frutty [35]

Forward reaction is a reaction in which products are produced from reactants and it goes from left to right in a reversible reaction.

For example, if the focus is on respiration, the forward reaction is written as
C6H12O6 + 6O2 ---> 6CO2 + 6H2O

If the focus is on photosynthesis, the forward reaction is written as
6CO2 + 6H2O ---> C6H12O6 + 6O2

8 0

3 years ago