Enter part(a), (c) with 2 siginificant digits and part(b) with 3 siginificant digits.

Enter scientific notation as 1.23E4.



(a) What is Ecell if the unknown solution in the half-cell on the left has pH = 4.94?



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(b) What is Ecell if the unknown solution in the half-cell on the left is 0.03890 M HCl?



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(c) What is Ecell if the unknown solution in the half-cell on the left is 0.194 M HA, where HA represents a weak acid with Ka = 1.8x10−5?



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To answer these questions, we need to use the Nernst equation, which relates the standard cell potential (E°cell) to the cell potential (Ecell) under non-standard conditions:

Ecell = E°cell - (0.0592/n) * log(Q)

where Ecell is the cell potential, E°cell is the standard cell potential, n is the number of electrons transferred in the balanced equation of the redox reaction, and Q is the reaction quotient.

(a) To find Ecell for a solution with a given pH, we need to consider the half-cell reaction and balanced equation. However, you did not provide the balanced equation for this reaction. Could you please provide more information on the half-cell reaction in order for me to help you further?

(b) To find Ecell for a 0.03890 M HCl solution, we need to consider the half-cell reaction and balanced equation. In this case, the balanced equation is:

H2(g) + 2e- -> 2H+(aq)

The number of electrons transferred (n) is 2. Since we are given the concentration of HCl, we can substitute it into the Nernst equation:

Ecell = E°cell - (0.0592/2) * log(Q)

Since HCl is a strong acid and fully dissociates in water, the reaction quotient Q is equal to the concentration of H+ ions, which is 0.03890 M.

Substituting the values into the equation:

Ecell = E°cell - (0.0296) * log(0.03890)

Now, you need to provide the value of E°cell for this half-cell reaction in order for me to find the final answer with 3 significant digits.

(c) To find Ecell for a 0.194 M HA solution, where HA represents a weak acid with Ka = 1.8x10⁻⁵, we again need the balanced equation for this half-cell reaction. Since you did not provide that information, could you please provide the balanced equation for this reaction so I can help you further?