Electrochemistry Flashcards
What is the battery process?
The battery process is when a spontaneous chemical reaction naturally creates a current.
What is the electrolysis process?
The electrolysis process describes when a non-spontaneous chemical reaction occurs only through the application of a current.
In the Daniell cell, what is the relationship between the composition of the electrode and the metallic ion solution it is immersed in?
The main metallic component of the electrode is also the element for the ion in the solution
What are cathodes and anodes?
Anodes: Electrode where the oxidation reaction occurs (loses electrons)
Cathode: Electrode where the reduction reaction occurs (gains electrons)
What is the total voltage of a battery circuit?
Voltage of anode reaction + voltage of cathode reaction
What is the global reaction of a battery process?
The summ of the two reactions without their common elements (electrons)
reagents in one side and products on the other side.
How to determine if a reaction is electrolytic or battery process based on it’s global reaction?
If the final voltage is positive it is a battery (spontaneous) process, if the final voltage is negative it is an electrolytic process
What is the salt bridge of the Daniell cell?
Due to the dumping of anode metal by the anode and the absorbption of cathode metal by the cathode, the ionic solutions will become positively and negatively charged, in order to avoid interference with the desired electron flow, a salt bridge is placed in contact with the two solutions, the salt will then deposit it’s anion in the anode solution and it’s cation on the cathode solution to neutralize it’s charges
What is the relationship of redox reactions, corrosion and deposition?
Oxidation of metals leads to their corrosion (loss of mass) and reduction of metals leads to the deposition/accumulation (gain of mass)
What is the relationship between the voltage of a particular reaction’s reduction side and it’s oxidation side?
The voltage of a reaction of oxidation is always the inverse sign of that reaction in it’s reduction version.
What is the standard hydrogen electrode and how does it work?
The standard hydrogen electrode, made with a bar filled with hydrogen gas (h2) inserted into a sulfuric acid solution (h2so4) is connected through a small platinum plate and wire inside the electrode to another semi-cell, by measuring the reduction and oxidation of the hydrogen electrode through pH measurements of the solution, it is possible to determine the reduction and oxidation tendency of the other electrode. The potential of the hydrogen electrode is always given as zero to serve as a standard. It is also possible to measure the voltage between the hydrogen electrode and the other electrode with a voltimeter
The standard hydrogen electrode set up utilizes a salt bridge too.
How to find the total difference in potential for two semi-reactions represented by the same type (reduction version or oxidation version) ?
Δ E⁰ = E⁰ Maior - E⁰ Menor
Maximum work of a voltaic cell equation
ΔG = -nFE
where F = avogadro’s number * charge of electron
What is qualitative electrolysis?
Qualitative electrolysis is concerned with the products formed by the electrolytic reaction.
What is the difference between igneous and aqueous electrolysis
Igneous: Happens without water, utilizes a liquified ionic compound
Aqueous: Happens with water, utilizes an aqueous solution of an ionic compound
