Help please, will mark you as brainliest

An electrochemical cell at 25°C is composed of pure copper and pure lead solutions immersed in their respective ionis. For a 0.6

ExtremeBDS [4]

Answer :

(a) The concentration of $Pb^{2+}$ is, 0.0337 M

(b) The concentration of $Pb^{2+}$ is, $6.093\times 10^{32}M$

Solution :

(a) As per question, lead is oxidized and copper is reduced.

The oxidation-reduction half cell reaction will be,

Oxidation half reaction: $Pb\rightarrow Pb^{2+}+2e^-$

Reduction half reaction: $Cu^{2+}+2e^-\rightarrow Cu$

The balanced cell reaction will be,

$Pb(s)+Cu^{2+}(aq)\rightarrow Pb^{2+}(aq)+Cu(s)$

Here lead (Pb) undergoes oxidation by loss of electrons, thus act as anode. Copper (Cu) undergoes reduction by gain of electrons and thus act as cathode.

First we have to calculate the standard electrode potential of the cell.

$E^o_{[Pb^{2+}/Pb]}=-0.13V$

$E^o_{[Cu^{2+}/Cu]}=+0.34V$

$E^o=E^o_{[Cu^{2+}/Cu]}-E^o_{[Pb^{2+}/Pb]}$

$E^o=0.34V-(-0.13V)=0.47V$

Now we have to calculate the concentration of $Pb^{2+}$ .

Using Nernest equation :

$E_{cell}=E^o_{cell}-\frac{0.0592}{n}\log \frac{[Pb^{2+}]}{[Cu^{2+}]}$

where,

n = number of electrons in oxidation-reduction reaction = 2

$E_{cell}$ = 0.507 V

Now put all the given values in the above equation, we get:

$0.507=0.47-\frac{0.0592}{2}\log \frac{[Pb^{2+}]}{(0.6)}$

$[Pb^{2+}]=0.0337M$

Therefore, the concentration of $Pb^{2+}$ is, 0.0337 M

(b) As per question, lead is reduced and copper is oxidized.

The oxidation-reduction half cell reaction will be,

Oxidation half reaction: $Cu\rightarrow Cu^{2+}+2e^-$

Reduction half reaction: $Pb^{2+}+2e^-\rightarrow Pb$

The balanced cell reaction will be,

$Cu(s)+Pb^{2+}(aq)\rightarrow Cu^{2+}(aq)+Pb(s)$

Here Copper (Cu) undergoes oxidation by loss of electrons, thus act as anode. Lead (Pb) undergoes reduction by gain of electrons and thus act as cathode.

First we have to calculate the standard electrode potential of the cell.

$E^o_{[Pb^{2+}/Pb]}=-0.13V$

$E^o_{[Cu^{2+}/Cu]}=+0.34V$

$E^o=E^o_{[Pb^{2+}/Pb]}-E^o_{[Cu^{2+}/Cu]}$

$E^o=-0.13V-(0.34V)=-0.47V$

Now we have to calculate the concentration of $Pb^{2+}$ .

Using Nernest equation :

$E_{cell}=E^o_{cell}-\frac{0.0592}{n}\log \frac{[Cu^{2+}]}{[Pb^{2+}]}$

where,

n = number of electrons in oxidation-reduction reaction = 2

$E_{cell}$ = 0.507 V

Now put all the given values in the above equation, we get:

$0.507=-0.47-\frac{0.0592}{2}\log \frac{(0.6)}{[Pb^{2+}]}$

$[Pb^{2+}]=6.093\times 10^{32}M$

Therefore, the concentration of $Pb^{2+}$ is, $6.093\times 10^{32}M$

6 0

3 years ago

Please help me i keep getting this wrong :(

solmaris [256]

A) A chandelier has been hanging in the kitchen for years
B) A log floats on top of the lake
C) You place your book on the top of a flat table

Those are the answers. In each case, there is always a force that balances the weight of the object and keeps them in a static equilibrium. Tension, Buoyancy and Normal force.

7 0

3 years ago

Minerals are _________ inorganic _________ that usually possess a crystalline structure and can be represented by a chemical for

ladessa [460]

Answer:

The corect answer is c) naturally occurring; solids

Explanation:

Minerals exists as solid substances in nature consisting of one or more element chemically combined together formiming compounds with definite composition. As mentioned earlier single elements can form minerals and examples of single element mineral are Silver, Carbon and Gold which are found in nature in their pure form and are mined.

Minerals are normally found in rocks, which may contain one ore more different types of minerals

7 0

3 years ago

Chemistry student needs of 55g acetone for an experiment. by consulting the crc handbook of chemistry and physics, the student d

sergeinik [125]

Answer:

70.15 cm³

Solution:

Data Given;

Mass = 55 g

Density = 0.784 g.cm⁻³

Required:

Volume = ?

Formula Used:

Density = Mass ÷ Volume

Solving for Volume,

Volume = Mass ÷ Density

Putting values,

Volume = 55 g ÷ 0.784 g.cm⁻³

Volume = 70.15 cm³

5 0

3 years ago

Which of the following are responsible for surface currents a. the wind and density

SCORPION-xisa [38]

B-wind and the earth's rotation

7 0

3 years ago

Read 2 more answers