Ask question

Ask question

All categories

3 years ago

11

2Co3+(aq)+2Cl−(aq)→2Co2+(aq)+Cl2(g). E∘=0.483 Vwhat is the cell potential at 25 ∘C if the concentrations are [Co3+]= 0.695 M , [

Co2+]= 0.175 M , and [Cl−]= 0.315 M and the pressure of Cl2 is PCl2= 8.50 atm ?

1 answer:

ch4aika [34]3 years ago

6 0

Answer:

The value of the cell potential under the given conditions is 0.433 V

Explanation:

The cellular potential is generally in standard conditions, that is, 1 M with respect to solute concentrations in solution and 1 atm for gases.

The Nernst equation is useful for finding the potential for reduction in electrodes under conditions other than standards. This is what happens in this case, since the concentrations are different than 1M and the gas pressure varies from the value 1 atm.

The Nernst equation is:

<em> $E=E^{o} -\frac{R*T}{n*F} *ln(Q)$ </em>

<em>Where E refers to the electrode potential. </em>

<em>Eº = potential in standard conditions. </em>

<em>R = gas constant. </em>

<em>T = absolute temperature (in Kelvin degrees). </em>

<em>n = number of moles of electrons that have participation in the reaction. </em>

<em>F = Faraday constant (with a value of 96500 C / mol, approx.) </em>

<em>Q = reaction ratio </em>

<em> When the reaction occurs at 25 ° C, the numerical value of the constants is replaced by 0.059, the expression being as follows:</em>

<em> $E=E^{o} -\frac{0.059}{n} *lnQ$ </em>

For the reaction aA + bB → cC + dD, Q adopts the expression:

$Q=\frac{C^{c} *D^{d} }{A^{a} *B^{b} }$

being for solutions the molar concentrations at any moment and for gases the pressure in atmospheres at any moment

In this case:

$Q=\frac{[Co^{+2}] ^{2}*P_{Cl2} }{[Co^{+3}] ^{2}*[Cl^{-}] ^{2} }$

$Q=\frac{[0.175M] ^{2}*8.5 }{[0.695M] ^{2}*[0.315M] ^{2} }$

<em>Q=5.43</em>

On the other hand, by observing the following semi-reactions it is possible to see that the number of moles of electrons n involved is 2:

2 Cl- ⇒ Cl₂ + 2 e-

2* [Co³⁺ + e- ⇒ Co²⁺ ]

So, the data to be able to calculate the electrode potential in the requested conditions is:

<em>E⁰=0.483 V</em>
<em>n=2</em>
<em>Q=5.43</em>

Replacing you get:

$E=0.483 -\frac{0.059}{2} *ln(5.43)$

<em>E=0.433 V </em>

So, <u><em>the value of the cell potential under the given conditions is 0.433 V</em></u>

You might be interested in

3. In what grade level do students grow the quickest?

Vadim26 [7]

Answer:

Independent Variable: Grade Level

Dependent Variable: Growth in height

Hypothesis: Students in [Insert the grade level you believe will grow the quickest here] will experience the quickest growth in height.

Explanation:

Independent variables are the factors in which you manipulate to gain your results, in this case you would be changing the grade level you would observe to see the height.

Dependent variables are the factors that respond to changes in the independent variables. You don't control these events, you simply observe them. In this case, you merely observe the growth in height in accordance to the different grade levels you observe.

For the hypothesis, you would create your own hypothesis based on a guess you have. You create a hypothesis not based on the data, but on what you believe will be correct before doing the experiment. It doesn't have to be the correct answer, but just your thoughts.

3 0

3 years ago

Describe the energy used for hydropower and the way in which it’s converted to electrical energy. Write 50 to 100 words.

Ratling [72]

Answer:

By taking advantage of gravity and the water cycle, we have tapped into one of nature's engines to create a useful form of energy. In fact, humans have been capturing the energy of moving water for thousands of years. Today, harnessing the power of moving water to generate electricity, known as hydroelectric power, is the largest source of emissions-free, renewable electricity in the United States and worldwide.

Although the generation of hydropower does not emit air pollution or greenhouse gas emissions, it can have negative environmental and social consequences. Blocking rivers with dams can degrade water quality, damage aquatic and riparian habitat, block migratory fish passage, and displace local communities. The benefits and drawbacks of any proposed hydropower development must be weighed before moving forward with any project. Still, if it's done right, hydropower can be a sustainable and nonpolluting source of electricity that can help decrease our dependence on fossil fuels and reduce the threat of global warming.

On Earth, water is constantly moved around in various states, a process known as the hydrologic cycle. Water evaporates from the oceans, forming into clouds, falling out as rain and snow, gathering into streams and rivers, and flowing back to the sea. All this movement provides an enormous opportunity to harness useful energy.

In 2011, hydropower provided 16 percent of the world’s electricity, second only to fossil fuels. Worldwide capacity in 2011 was 950 gigawatts (GW), with 24 percent in the China, eight percent in the United States, and nine percent in Brazil [1]. Globally, hydroelectric capacity has more than doubled since 1970.

In the United States, hydropower has grown steadily, from 56 GW of installed capacity in 1970 to more than 78 GW in 2011 [2]. However, as a percentage of total U.S. electricity generation, it has fallen from 12 percent in 1980 to 7 percent in 2012, largely as a result of the rapid growth in natural gas power plants and other renewable energy technologies such as wind and solar [3].

Since hydropower depends on rivers and streams for generation, the potential to use hydropower as a source of electricity varies across the country. For example, the Pacific Northwest (Oregon and Washington) generates more than two-thirds of its electricity from hydroelectric dams [4]. The Grand Coulee dam on the Columbia River in Washington is one of the largest dams in the world, with a capacity of more than 6,750 megawatts (MW).

In addition to very large plants in the western states, the United States has many smaller hydropower plants. In 1940 there were 3,100 hydropower plants across the country, though by 1980 that number had fallen to 1,425. Since then, a number of these small plants have been restored; as of 2013, there were 1,672 hydro plants (not including pumped storage) in operation [5]. These plants account for only a tiny fraction of the dams that block and divert our rivers.

I hope it helps

8 0

3 years ago

__Zn + __HCl --> __ZnCl2 + __H2

mylen [45]

Answer:

1. The balanced equation:

Zn + 2HCl —> ZnCl₂ + H₂

The coefficients are: 1, 2, 1, 1

2. 2.34 moles of HCl

Explanation:

1. The balanced equation

__Zn + __HCl —> __ZnCl₂ + __H₂

There are 2 atoms of H on the right side and 1 atom on the left side

It can be balance by writing 2 before HCl as shown below:

Zn + 2HCl —> ZnCl₂ + H₂

Now the equation is balanced.

The coefficients are: 1, 2, 1, 1

2. Determination of the number of mole of HCl that reacted.

NOTE: 1 mole of H₂ = 22.4 L at STP.

Zn + 2HCl —> ZnCl₂ + H₂

From the balanced equation above,

2 moles of HCl reacted to produce 1 mole (i.e 22.4 L) of H₂.

Finally, we shall determine the number of mole of HCl needed to produce 26.22 L of H₂. This can be obtained as follow:

From the balanced equation above,

2 moles of HCl reacted to produce 22.4 L of H₂.

Therefore, Xmol of HCl will react to produce 26.22 L of H₂ i.e

Xmol of HCl = (2 × 26.22)/22.4

Xmol of HCl = 2.34 moles

Thus, 2.34 moles of HCl is needed for the reaction.

5 0

3 years ago

8. Build a neutral lithium atom.

choli [55]

Answer:

Remove 1 electron

Explanation:

In the atom of each element, there are three subatomic particles viz: proton, neutron and electron. The number of proton (positively charged) and electron (negatively charged) determines the charge of that element. The more the proton, the more positively charged an ion is and vice versa for electron.

According to this question, a neutral atom of lithium (Li) with atomic no. 3 is given i.e. a lithium atom with charge 0. To make the lithium atom's charge change to +1, ONE ELECTRON MUST BE REMOVED OR LOST.

Note that, the proton number (atomic number) of an element does not change, rather the electron number changes in relation to the no. of protons.

3 0

3 years ago

Which topic might interest a sociologist

masha68 [24]

Are there answer choices?? anything that would be pertaining to social working basically any media or social matter

8 0

3 years ago

Read 2 more answers