What are all the oceans combined called?

Determine which of the following pairs of reactants will result in a spontaneous reaction at 25°C. None of the above pairs will

Alla [95]

Answer:

Only $Fe^{3+}+Mg$ gives spontaneous reaction.

Explanation:

A redox reaction will be spontaneous if standard reduction potential ( $E^{0}$ ) of the reaction is positive. Because it leads to negative standard gibbs free energy change ( $\Delta G^{0}$ ), which is a thermodynamic condition for spontaneity of a reaction.

$E^{0}=E^{0}(reduction)-E^{0}(oxidation)$

Where $E^{0}(reduction)$ and $E^{0}(oxidation)$ represents standard reduction potential of reduction half cell and standard reduction potential of oxidation half cell.

(1) Oxidation: $Mg-2e^{-}\rightarrow Mg^{2+}$ ; $E_{Mg^{2+}\mid Mg}^{0}=-2.38V$

Reduction: $Fe^{3+}+3e^{-}\rightarrow Fe$ ; $E_{Fe^{3+}\mid Fe}^{0}=-0.04V$

So, $E^{0}=E_{Fe^{3+}\mid Fe}^{0}-E_{Mg^{2+}\mid Mg}^{0}=(-0.04+2.38)V=2.34V$

Hence this pair will give spontaneous reaction.

(2) Similarly as above, $E^{0}=E_{Pb^{2+}\mid Pb}^{0}-E_{Au^{+}\mid Au}^{0}=(-0.13-1.69)V=-1.82 V$

Hence this pair will give non-spontaneous reaction.

(3) Similarly as above, $E^{0}=E_{Ag^{+}\mid Ag}^{0}-E_{Br_{2}\mid Br^{-}}^{0}=(0.80-1.07)V=-0.27 V$

Hence this pair will give non-spontaneous reaction.

(4) Similarly as above, $E^{0}=E_{Li^{+}\mid Li}^{0}-E_{Cr^{3+}\mid Cr}^{0}=(-3.04+0.74)V=-2.30 V$

Hence this pair will give non-spontaneous reaction.

6 0

3 years ago

What is the name for Si3S

sesenic [268]

Answer:

Silicopropane

Explanation:

7 0

2 years ago

If the energy of photon emitted from the hydrogen atom is 4.09 x 10-19 J, what is

Aliun [14]

Answer:

486 nm

Explanation:

From the question given above, the following data were obtained:

Energy (E) = 4.09×10¯¹⁹ J

Wavelength (λ) =?

Next, we shall determine the frequency of the photon. This can be obtained as follow:

Energy (E) = 4.09×10¯¹⁹ J

Planck's constant (h) = 6.63×10¯³⁴ Js

Frequency (f) =?

E = hf

4.09×10¯¹⁹ = 6.63×10¯³⁴ × f

Divide both side by 6.63×10¯³⁴

f = 4.09×10¯¹⁹ / 6.63×10¯³⁴

f = 6.17×10¹⁴ Hz

Next, we shall determine the wavelength of the photon. This can be obtained as follow:

Frequency (f) = 6.17×10¹⁴ Hz

Velocity of photon (v) = 3×10⁸ m/s

Wavelength (λ) =?

v = λf

3×10⁸ = λ × 6.17×10¹⁴

Divide both side by 6.17×10¹⁴

λ = 3×10⁸ / 6.17×10¹⁴

λ = 4.86×10¯⁷ m

Finally, we shall convert 4.86×10¯⁷ m to nm. This can be obtained as follow:

1 m = 1×10⁹ nm

Therefore,

4.86×10¯⁷ m = 4.86×10¯⁷ m × 1×10⁹ nm / 1 m

4.86×10¯⁷ m = 486 nm

Therefore, the wavelength of the photon is 486 nm

7 0

3 years ago

A chemical engineer must calculate the maximum safe operating temperature of a high-pressure gas reaction vessel. The vessel is

Anuta_ua [19.1K]

The maximum safe operating temperature for this reaction is equal to 895°C.

<u>Given the following data:</u>

Width of cylinder = 22 cm.

Height, h = 26.4 cm.

Maximum safe pressure = 6.30mpa.

Mass = 0.537 kg.

<u>Scientific data:</u>

Ideal gas constant, R = 8.314 L-kPa/Kmol.

Molar mass of of dinitrogen monoxide ( $N_2F_2$ ) gas = 66 g/mol.

Radius, r = $\frac{width}{2} =\frac{22}{2} =11\;cm$

<h3>How to calculate the maximum safe operating temperature.</h3>

First of all, we would determine the volume of the stainless-steel cylinder by using this formula:

$V=\pi r^2 h\\\\V = 3.142 \times 11^2 \times 26.4\\\\$

Volume, V = 10,036.81 $cm^3$ .

In liters, we have:

Volume, V = 10.04 Liters.

Next, we would determine the number of moles of dinitrogen monoxide ( $N_2F_2$ ) gas:

$Number \;of \;moles = \frac {mass}{molar\;mass}\\\\Number \;of \;moles = \frac {537}{66}$

Number of moles = 8.136 moles.

Now, we can solve for the maximum safe operating temperature by applying the ideal gas equation:

$PV=nRT\\\\T=\frac{PV}{nR} \\\\T=\frac{6.30 \times 10^3 \times 10.04}{8.136 \times 8.314}\\\\T=\frac{60541.2}{67.6427}$

T = 895.02 ≈ 895°C.

Read more on temperature here: brainly.com/question/24769208

5 0

2 years ago

An ideal gas at constant temperature is confined in an airtight cylinder, and a piston pushes down on the gas in the cylinder. a

FrozenT [24]

Pushing down a piston in an airtight cylinder would tend to increase the pressure in the system since the particle collision and collisions with the walls are now more frequent. Also, pushing further, the gas would undergo a phase change from gas to a liquid.

3 0

3 years ago