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3 years ago

Calculate the maximum amount of useful work that can be obtained and comment on the spontaneity for the reaction at 25C :

Chemistry

1 answer:

harkovskaia [24]3 years ago

3 0

Answer:

$1.41 *10^{3} kJ/mol$

Explanation:

First, we find in the tables the ΔH of formation of each compound. As you can see in the (image 1)

Then we solve the ecuation for ΔH°reaction

ΔH°reaction=∑ΔH°f(products)−∑ΔH°f(Reactants)

ΔH°reaction= (-2* 393.5 - 2*285.8) - (52.4 + 0) kJ/mol

ΔH°reaction = -1.41 *10^3 kJ/mol

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Classify which compounds will dissolve in water and which ones will not dissolve in water.

vredina [299]

Answer:

Dissolves in water: Acetone, 1-propanol, Methanol

Do not dissolve in water: Hexane, Decane

Explanation:

From the principle that like dissolves like,polar substances will dissolve in polar solutions, while non-polar substances will dissolve in non-polar substances.

Water is a polar solution, therefore, polar substances will dissolve in it.From the given options:

Acetone is a polar molecule, therefore, it will dissolve in water.

1-propanol is a polar molecule, therefore, it will dissolve in water.

Hexane is a non-polar molecule, therefore, it will not dissolve in water.

Methanol is a polar molecule, therefore, it will dissolve in water.

Decane is a non-polar molecule, therefore, it will not dissolve in water

6 0

2 years ago

True or false: The Earth's rotation causes the winds to curve.

Rashid [163]

Answer:

true

Explanation:

3 0

2 years ago

A cleaning bottle contains 83.1 g of ammonia. How many molecules of ammonia are in the bottle?

Tasya [4]

Answer:

2.94 x $10^2^4$

Explanation:

First we need to find out how many moles of ammonia there are, using the formula: Mass = mr x moles.

We know the mass is 83.1g, now we need to find the mR of ammonia - NH3.

N = 14, H = 1, so 14 + (3x1) = an mr of 17.

Moles = mass/ mr = 83.1/17 = 4.8882

Now we can multiply the moles by avogadro's constant to find the number of molecules:

4.8882 x (6.02 x $10^2^3$ ) = 2.94 x $10^2^4$ molecules of ammonia

4 0

3 years ago

Liquid A is known to have a lower surface tension and lower viscosity than Liquid B. Use these facts to predict the result of be

Korvikt [17]

Answer: Option (B) is the correct answer.

Explanation:

Surface tension is defined as the attractive forces experienced by the surface molecules of a liquid by the molecules present beneath the surface layer of the liquid.

And, viscosity is defined as the ability of a liquid to resist its flow. When a substance has high viscosity then it is known as a viscous substance.

Since, it is given that viscosity of liquid B is more than liquid A. Therefore, liquid B has more resistive force on its surface as compared to liquid A. As a result, time taken by liquid B is more than time taken by liquid A.

Also, Surface tension = $\frac{Force}{Length}$

Surface tension of liquid B is more than liquid A. Therefore, $F_{B} > F_{A}$ .

Thus, we can conclude that tA will be less than tB.

8 0

2 years ago

Nitrogen gas is being withdrawn at the rate of 4.5 g/s from a 0.15-m3 cylinder, initially containing the gas at a pressure of 10

faust18 [17]

Answer:

Final temperature = 152.57K,

Pressure = 0.6907 bar.

dT/dt = - 1,151 K/s.

Explanation:

The first thing to do here is to write out the equation for mass balance as given below:

dN/dt = N -------------------------------------------------------------------------------------------(1).

N = P/T, then, substitute the values given in the question into:

d[p/T]/ dt = [- 4.5/28 × 8.314]/0.15 = - 8.9 × 10⁻⁵ bar/K.s.

Thus, there is the need to integrate, Integrate [p/T]f = 10/320 - 8.9 × 10⁻⁵ bar/K.s. ------------------------------------(2).

NB; fT = final temperature, fP = final pressure and iT = initial temperature.

Also, [ fT]³⁰/₈.₃₁₄/ [fP] = [iT]³⁰/₈.₃₁₄/ Pi] = [ 320]³⁰/₈.₃₁₄/ 10.

Therefore, [fT]³⁰/₈.₃₁₄ = 109.52 × 10⁶.

Final temperature= [fP]³⁰/₈.₃₁₄ × 169.05.

Note that fP/ [fP]³⁰/₈.₃₁₄ × 169.05 = 10/320 - 8.9 × 10⁻⁵.

Therefore, [fP]¹ ⁻ ³⁰/₈.₃₁₄ = 0.7651.

Hence, Final temperature = 152.57K,

Pressure = 0.6907 bar

dT/ dt = N[RT]² / Cv . PV.

R = 30 - 8.314 = 21.86 J/mol K.

Then, the rate of change of the gas temperature at this time = dT/dt = - 1,151 K/s.

4 0

2 years ago