One liter equals the volume of a 10 cubic centimeters. True False

At 85°C, the vapor pressure of A is 566 torr and that of B is 250 torr. Calculate the composition of a mixture of A and B that b

Phantasy [73]

Answer:

Composition of the mixture:

$x_{A} =0.652=65.2$ %

$x_{B} =0.348=34.8$ %

Composition of the vapor mixture:

$y_{A} =0.809=80.9$ %

$y_{B} =0.191=19.1$ %

Explanation:

If the ideal solution model is assumed, and the vapor phase is modeled as an ideal gas, the vapor pressure of a binary mixture with $x_{A}$ and $x_{B}$ molar fractions can be calculated as:

$P_{vap}=x_{A}P_{A}+x_{B}P_{B}$

Where $P_{A}$ and $P_{B}$ are the vapor pressures of the pure compounds. A substance boils when its vapor pressure is equal to the pressure under it is; so it boils when $P_{vap}=P$ . When the pressure is 0.60 atm, the vapor pressure has to be the same if the mixture is boiling, so:

$0.60*760=P_{vap}=x_{A}P_{A}+x_{B}P_{B}\\456=x_{A}P_{A}+(1-x_{A})P_{B}\\456=x_{A}*(P_{A}-P_{B})+P_{B}\\\frac{456-P_{B}}{P_{A}-P_{B}}=x_{A}\\\\\frac{456-250}{566-250}=x_{A}=0.652$

With the same assumptions, the vapor mixture may obey to the equation:

$x_{A}P_{A}=y_{A}P$ , where P is the total pressure and y is the fraction in the vapor phase, so:

$y_{A} =\frac{x_{A}P_{A}}{P}=\frac{0.652*566}{456} =0.809=80.9$ %

The fractions of B can be calculated according to the fact that the sum of the molar fractions is equal to 1.

7 0

3 years ago

What is the mole fraction of HCl in a solution that contains 0.99 mole HCl and 3.6 mole H2O

marysya [2.9K]

Answer:

0.216

Explanation:

The mole fraction of HCl is the number of moles of HCl (0.99) divided by the total number of moles in the solution.

mole fraction = (0.99)/(0.99 +3.6) = 0.2157

The mole fraction of HCl is about 0.216.

4 0

3 years ago

A characteristic of a substance that may be observed or measured without changing the composition of the substance is a(n) ___ p

ivann1987 [24]

Answer:

c physical

Explanation:

5 0

3 years ago

Consider the following reaction at equilibrium. 2CO2 (g) 2CO (g) + O2 (g) H° = -514 kJ Le Châtelier's principle predicts that th

tiny-mole [99]

Answer:

C. at low temperature and low pressure.

Explanation:

Le Châtelier's principle states that when there is an dynamic equilibrium, and this equilibrium is disturbed by an external factor, the equilibrium will be shifted in the direction that can cancel the effect of the external factor to reattain the equilibrium.

For the reaction:

2CO₂(g) ⇄ 2CO(g) + O₂(g), ΔH = -514 kJ.

Effect of pressure:

When there is an increase in pressure, the equilibrium will shift towards the side with fewer moles of gas of the reaction. And when there is a decrease in pressure, the equilibrium will shift towards the side with more moles of gas of the reaction.

The reactants side (left) has 2.0 moles of gases and the products side (right) has 3.0 moles of gases.

So, decreasing the pressure will shift the reaction to the side with higher no. of moles of gas (right side, products), so the equilibrium partial pressure of CO (g) can be maximized at low pressure.

Effect of temperature:

The reaction is exothermic because the sign of ΔH is (negative).

So, we can write the reaction as:

2CO₂(g) ⇄ 2CO(g) + O₂(g) + heat.

Decreasing the temperature will decrease the concentration of the products side, so the reaction will be shifted to the right side to suppress the decrease in the temperature, so the equilibrium partial pressure of CO (g) can be maximized at low temperature.

So, the right choice is:

C. at low temperature and low pressure.

7 0

4 years ago

Which scenario would result in the fastest rate of dissolution?

soldi70 [24.7K]

C) powdered sugar in hot water because the sugar is already broken so it would be more faster than sugar cube in hot water

4 0

3 years ago

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