All definitions in Chem Flashcards
Salt
(An ionic compound consisting of a cation such as a metal ion or an ammonium ion from a base and an anion from an acid)
A compound formed when the hydrogen ion in an acid is replaced by a metal ion or an ammonium ion
Recrystallisation
Carried out to obtain pure crystals of the salt from its solution
Titration
Carried out to determine the exact volume of an acid needed to neutralise a fixed volume of an alkali solution with the help of an indicator
Crystallisation
Carried out to obtain crystals of the salt
Double decomposition method
Two aqueous solutions of two different soluble salts are mixed together to form the insoluble salt
Precipitate
A solid substance formed during a reaction occurring in a solution
Qualitative analysis
A chemical technique used to identify the ions present in a salt by analysing its physical and chemical properties and hence determine the identity of salt
Electrolytes
Substances that can conduct electricity either in the molten state or in an aqueous solution and undergo chemical changes
Non-electrolytes
Substances that cannot conduct electricity either in the molten state or in an aqueous solution
Conductors
Substances that can conduct electricity in the solid or molten state but are not chemically changed
Hence, conductors are not electrolytes
Ionic compound
Do not conduct electricity in the solid state because the ions are held in a lattice and do not move freely
Covalent compound
Exist as molecules in an organic solvent, do not conduct electricity in an organic solvent such as methylbenzene
Electrolysis
A process whereby a compound is decomposed into its consistuent elements when an electric current passes through an electrolyte
Electrode
A conductor in the form of a wire, rod or plate which carries electric current in and out of the electrolyte during electrolysis
Active electrode
An electrode which takes part in chemical reactions during electrolysis
Inert electrode
An electrode which does not take part in chemical reactions during electrolysis
Aqueous solution
A solution produced when the compound is dissolved in water
Electroplating
A process of depositing a layer of metal on another substance using electrolysis
Voltaic cell
aka galvanic cell
A device which converts chemical energy to electrical energy
Anode
The electrode where the process of donation of electrons takes place
In electrolysis, the anode is positively charged
In a voltaic cell, the anode is negatively charged
Cathode
The electrode where the process of acceptance of electrons take place
In electrolysis, the anode is negatively charged
In a voltaic cell, the anode is positively charged
Insoluble salts
Formed as a precipitate when two aqueous solutions of two different soluble salts are mixed together
Electrochemical series
An arrangement of metals based on the tendency of each metal atom to donate electrons
Metal displacement reaction
A metal is situated at a higher position in the electrochemical series is able to displace a metal below it in the series from its salt solution
(This happens because metals with higher positions have a greater tendency to form positive ions)
Acid
A substance which dissociates in water to produce hydrogen ions
Hydroxonium ion
The hydrogen ion that attaches itself to a water molecule
Monoproctic acid
An acid that contains only one ionisable hydrogen atom, producing only one hydrogen ion per molecule of acid
Polyprotic acid
An acid that can produce more than one hydrogen ion per molecule of acid
Basicity
The number of ionisable hydrogen atoms per molecule of acid
Acidic oxides
Non-metal oxides which react with water to produce acidic solutions which contain hydrogen ions
Mineral acids
Obtained from minerals
Organic acids
Extracted from animal and plant materials