The relationship between the concentration of the electrolyte and the cell potential is investigated using the following electrochemical cell represented by the cell notation: A(s) | A²⁺(aq) || M²⁺(aq) | M(s) The concentration of M²⁺ is changed and the corresponding emf is measured. The concentration of A²⁺(aq) and the temperature are at standard conditions. The graph below shows the results of this investigation. 8.1 Identify the reducing agent in this cell. 8.2 Determine the concentration of M²⁺(aq) that will produce an emf of 1,87 V. 8.3 How will the concentration of M²⁺(aq) be affected as the cell operates? Choose from INCREASES, DECREASES or REMAINS THE SAME. Give a reason for the answer. 8.4 Potassium nitrate, KNO₃, is used in the salt bridge (At or M)?

NSC Physical Sciences Electrochemistry: The relationship between the con

The relationship between the concentration of the electrolyte and the cell potential is investigated using the following electrochemical cell represented by the cell notation: A(s) | A²⁺(aq) || M²⁺(aq) | M(s) The concentration of M²⁺ is changed and the corresponding emf is measured - NSC Physical Sciences - Question 8 - 2024 - Paper 2

Question 8

The relationship between the concentration of the electrolyte and the cell potential is investigated using the following electrochemical cell represented by the cell... show full transcript

Worked Solution & Example Answer:The relationship between the concentration of the electrolyte and the cell potential is investigated using the following electrochemical cell represented by the cell notation: A(s) | A²⁺(aq) || M²⁺(aq) | M(s) The concentration of M²⁺ is changed and the corresponding emf is measured - NSC Physical Sciences - Question 8 - 2024 - Paper 2

Step 1

8.1 Identify the reducing agent in this cell.

96%

114 rated

Answer

The reducing agent in the given electrochemical cell is Aluminum (Al). In redox reactions, the reducing agent is the species that donates electrons and gets oxidized.

Step 2

8.2 Determine the concentration of M²⁺(aq) that will produce an emf of 1,87 V.

99%

104 rated

Answer

To find the concentration of M²⁺(aq) that yields an emf of 1.87 V, we utilize the Nernst equation:

$E = E^\circ - \frac{RT}{nF} \ln Q$

For this reaction at standard conditions (25°C), the concentration of A²⁺ will influence the concentration of M²⁺. Rearranging the equation will give the concentration as approximately 0.325 mol/dm³ based on the values provided.

Step 3

8.3 How will the concentration of M²⁺(aq) be affected as the cell operates? Choose from INCREASES, DECREASES or REMAINS THE SAME.

96%

101 rated

Answer

The concentration of M²⁺(aq) will DECREASE as the cell operates. This is because, as the cell operates, M²⁺ ions are being consumed as they undergo reduction at the cathode.

Step 4

Give a reason for the answer.

98%

120 rated

Answer

As the electrochemical cell runs, the reduction process consumes M²⁺ ions to form M(s), thereby decreasing the concentration of M²⁺ in the solution.

Step 5

8.4 Potassium nitrate, KNO₃, is used in the salt bridge (At or M)?

97%

117 rated

Answer

KNO₃ is used in the salt bridge to maintain electrical neutrality by allowing the flow of K⁺ ions towards the cathode and NO₃⁻ ions towards the anode. Therefore, it can be stated that K⁺ ions move in the salt bridge towards the A(s) (At).

8.1 Identify the reducing agent in this cell.

8.2 Determine the concentration of M²⁺(aq) that will produce an emf of 1,87 V.

8.3 How will the concentration of M²⁺(aq) be affected as the cell operates? Choose from INCREASES, DECREASES or REMAINS THE SAME.

Give a reason for the answer.

8.4 Potassium nitrate, KNO₃, is used in the salt bridge (At or M)?

Join the NSC students using SimpleStudy...