Potensial elektroda dan potensial elektroda standar

Summary

This educational video explores the concept of electrode potential and standard electrode potential in electrochemistry. It explains the role of electrodes in oxidation and reduction reactions, focusing on the standard hydrogen electrode (SHE) as a reference. The video covers the calculation of electrode potentials and the reactivity series, highlighting how to measure electrode potential in electrochemical cells. Additionally, it provides insights into constructing and writing notations for voltaic cells, aiding in the understanding of electrochemical reactions in practical scenarios such as batteries and corrosion prevention.

Takeaways

• 😀 Potential electrode refers to the potential generated by a metal electrode when placed in an electrolyte solution.
• 😀 An electrode that releases electrons during oxidation is called the oxidation electrode, while one that accepts electrons during reduction is called the reduction electrode.
• 😀 Standard electrode potential is compared using a reference electrode, usually the hydrogen electrode, which is set at 0.00V.
• 😀 The platinum electrode is used in the standard hydrogen electrode (SHE) to measure the potential in a solution with a 1 molal concentration of hydrogen gas at 1 atmosphere pressure.
• 😀 Electrochemical cells can be measured using a voltmeter, and the standard electrode potentials are used as a reference point for comparison.
• 😀 The reduction of a metal ion in a solution is marked by the acceptance of electrons, which makes the metal ion reduce to a solid metal.
• 😀 To measure electrode potential, a secondary electrode is compared with a standard hydrogen electrode, and the voltage difference is recorded.
• 😀 The electrode potential of a metal can help determine whether it is more likely to undergo oxidation or reduction in a specific environment.
• 😀 A voltaic series (or electrochemical series) arranges elements according to their standard reduction potentials, with metals on the left being more reactive (more easily oxidized).
• 😀 By understanding the standard electrode potentials, one can calculate the potential of a galvanic cell and predict the direction of the redox reaction occurring within it.

Q & A

What is the standard electrode potential?

The standard electrode potential refers to the potential created by a metal electrode when it is placed in a solution of its ions at a concentration of 1 mol/L and at a pressure of 1 atm. It is used to measure the tendency of a metal to undergo oxidation or reduction.

What does the term 'electrode potential' refer to?

Electrode potential refers to the electric potential generated by a metal electrode when it is in contact with its ion solution. This potential can be positive (reduction) or negative (oxidation).

Why is a standard electrode potential necessary for comparison?

Since electrode potential cannot be measured directly, a reference or standard electrode, such as the hydrogen electrode, is used to compare and measure other electrode potentials.

What is the function of a platinum electrode in the standard electrode potential measurement?

A platinum electrode is used as a conductive surface when measuring the standard electrode potential, especially when the reaction involves gases, like hydrogen, where platinum does not participate in the reaction but facilitates electron transfer.

How is a standard hydrogen electrode (SHE) used in electrochemical measurements?

The standard hydrogen electrode (SHE) is used as a reference electrode. It involves platinum coated with hydrogen gas at 1 atm pressure, in a solution with a concentration of 1 mol/L of H+ ions. This setup has a potential of 0.00 V and serves as the basis for comparing other electrode potentials.

How do you measure the standard electrode potential of a metal like copper (Cu)?

To measure the standard electrode potential of a metal like copper, it is compared with the standard hydrogen electrode. A voltmeter is used to measure the potential difference, and the value is recorded. For example, the standard electrode potential of Cu is +0.34 V.

What is the relationship between electrode potential and reactivity of metals?

The reactivity of metals can be determined by their electrode potentials. Metals with more positive electrode potentials tend to be better at accepting electrons (reduction), while those with more negative potentials are more likely to lose electrons (oxidation).

How does the electrochemical series help in understanding the reactivity of metals?

The electrochemical series arranges elements based on their standard electrode potentials. Metals higher in the series are more likely to undergo reduction, while those lower in the series are more easily oxidized. It helps predict the reactivity of metals.

What is the purpose of a salt bridge in an electrochemical cell?

A salt bridge is used in electrochemical cells to maintain electrical neutrality by allowing the flow of ions between the two half-cells. It prevents the buildup of charge and ensures the continuity of the reaction.

How do you calculate the cell potential in an electrochemical reaction?

To calculate the cell potential, the standard electrode potentials of the two half-reactions are subtracted. The formula is E(cell) = E(reduction) - E(oxidation). The result gives the potential difference between the anode and cathode.