Question

Standard electrode potential of SHE at \(298 \mathrm{~K}\) is : (a) \(0.05 \mathrm{~V}\). (b) \(0.10 \mathrm{~V}\) (c) \(0.50 \mathrm{~V}\) (d) \(0.00 \mathrm{~V}\)

Short answer

The standard electrode potential of SHE at 298 K is (d) 0.00 V.

Step-by-step solution

Understanding Standard Electrode Potential

Standard Electrode Potential, often represented by the symbol E°, is the measure of a potential difference for a chemical system. For the Standard Hydrogen Electrode (SHE), it is arbitrarily assigned a value of 0.00 V at 298 K, which serves as the reference electrode for all redox reactions.

Identifying the Value for SHE

Using the provided information, identify from the given options the value that is recognized as the standard electrode potential for the Standard Hydrogen Electrode (SHE) at 298 K.

Selecting the Correct Answer

Based on the definition of standard electrode potential for SHE at 298 K, the correct answer is the assigned value of 0.00 V, which is the potential difference used as a reference in electrochemistry.

Key concepts

Standard Hydrogen Electrode (SHE)

The Standard Hydrogen Electrode (SHE) serves as a universal reference for measuring and comparing the electrochemical potentials of different electrodes. It is a crucial component in the field of electrochemistry because it provides a baseline from which all other electrodes can be measured. Imagine the SHE as the 'zero point' or 'ground level' from which all other potentials are evaluated.

The SHE consists of a platinum electrode coated with platinum black, immersed in a solution of 1M acid, and hydrogen gas bubbled through it at 1 atmosphere pressure. Both the acid concentration and the gas pressure are significant: they must be exactly 1M and 1 atmosphere, respectively, to ensure that the SHE functions at the standard state.

Redox Reactions

Redox reactions are chemical processes involving the transfer of electrons between two species. It's like a dance of electrons, where one dance partner (the reducing agent) gives up an electron and the other (the oxidizing agent) takes it. This transfer results in changes in the oxidation states of the involved species. Every redox reaction comprises two half-reactions: one for oxidation and one for reduction. They play leading roles in various aspects of chemistry and are integral to processes like corrosion, energy production, and metabolism.

The connection between redox reactions and the SHE comes into play when measuring the potential difference. By comparing the potential of an unknown electrode to the SHE, we can deduce how electrons will flow during a reaction, essentially predicting which substances will be oxidized and which will be reduced.

Electrochemistry

Electrochemistry is the branch of chemistry that deals with the relationship between electrical energy and chemical changes—which is an intriguing blend of electrons in motion and atoms reconfiguring themselves. In this field, we study phenomena such as galvanic cells, where chemical energy is transformed into electrical energy, and electrolytic cells, where the process is reversed.

Understanding the standard electrode potential is key in electrochemistry because it allows us to predict the direction of electron flow in these cells. This, in turn, helps in designing batteries and in processes like electroplating. Moreover, mastering electrochemistry principles opens the door to advances in areas such as energy storage (think about next-gen batteries), corrosion prevention, and electro-synthesis of compounds.

Chemical Systems

Chemical systems encompass the entirety of substances and conditions involved in a chemical process. Think of a chemical system as a stage where the actors (reactants) perform under the guidance of the director (conditions like temperature and pressure) to create a masterpiece (products). Each system has its characteristics determined by the specifics of its composition, and this is where the standard electrode potentials come into play.

Standard conditions, such as those used in setting the standard electrode potential of the SHE, are a sort of 'script' that all chemical systems 'read from' to ensure consistency and comparability in results. The ability to compare different chemical systems under standardized conditions is invaluable, enabling scientists and engineers to make predictions and design processes across the vast landscape of chemistry.