Electolytic Process, Obataining And Using Metals, Etc Flashcards
What is an electrolyte?
When an ionic solid is melted or dissolved in water, it’s ionic bonds break. This allow the ions to move. An ionic substance with freely moving electrons is called an electrolyte
What is electrolysis?
The process in which energy transferred by a direct electrical current decomposes electrolysis, it is used to brea down many substances
What is used in electrolysis?
Energy transferred by electricity to decompose electrolytes. Two electrodes are connected to a direct current (d.c) electricity supply and placed into the electrolyte. The two types of ions carry opposite charges and so migrate (move) towards the electrode with the opposite charge
What are cations?
Positive ions and are attracted to the negative cathode
What are anions?
Negative ions and are attached to the positive anode
What is oxidation?
Loss of electrons or gain of oxygen
What is reduction?
Gain of electrons or loss of oxygen
Where does reduction take place?
At the cathode
Where does oxidation take place?
At the anode
Show a cathode reaction
Zn + 2e ➡️ Zn
Show an anode reaction
2Cl ➡️ Cl + 2e
How is the electrolysis of molten or dissolved ionic salts carried out?
Using inert (unreactive) electrodes (usually graphite or platinum). When a molten salt is electrolysed, ions are discharged as atoms or molecules at the electrodes. When molten lead bromide is electrolysed, bromine is produced at the anode and lead is produced at the cathode
How can you predict the electrolysis products of any molten salt?
The salt will always decompose into its elements. The metal is produced at the cathode and the non-metal is produced at the anode
explain electrolysis of salt solutions using copper chloride as an example
At the cathode Cu 2+ and H+ ions are attracted. Copper ions are dirchsrged more readily tau. Hydrogen ions, so copper is formed as a brown solid.
At the anode Cl- and OH- ions are attracted. Chloride ions are discharged more readily than hydroxide ions, so chlorine is formed as a pale green gas. Overall the copper chloride decomposes but the water does not change
During the electrolysis of water acidified with dilute sulfuric acid what happens?
Water decomposes to form hydrogen and oxygen
How can copper be purified by the electrolysis of copper suk fate solution using copper electrodes?
The copper atoms in the anode lose electrons to be come copper ions. These dissolve in the solution and migrate to the cathode, where they are deposited as pure copper. Impurities from the anode do not from ions and collect below the anode as a sludge
What is the reactivity series?
A list of mental in order of reactivity, within the most reactive at the top
List the reactivity series
Potassium Sodium Calcium Magnesium Aluminium Zinc Iron Copper Silver Gold
The higher the metal is in the reactivity series, the mire easily…….
A metals atom loses eke robs
Metal atoms lose electrons to from what?
Positive ions
How can we use the reactivity series to predict whether reactions will take place?
Each metal will react with compounds of the metals below it in the series
What cannot copper displace zinc from its compounds!
Because copper is less reactive
What is a displacement reaction?
When a more reactive element displaces a less reactive element from one of its compounds
What is a redox reaction?
A reaction in which one substance is oxidised and another is reduced