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During electrolysis, substances like oxygen gas, chlorine gas, bromine etc. are liberated at the anode depending on the electrolytes used, while substances like hydrogen gas, copper, silver etc. are liberated or deposited at the cathode. The volume of gases liberated or mass of metals deposited depend on the amount of electricity that is passed, be it carried out on one or more electrolytes. These relationships were summarized by Michael Faraday into what are now known as the Laws of Electrolysis. Faraday's 1st Law of Electrolysis This law states that the mass of a substance deposited or liberated at the electrodes during electrolysis is directly proportional to the quantity of electricity passed through the electrolyte. Mathematically, this can be expressed as:                           m α Q ..................................(i) where, m = mass in grams (g); and Q = quantity of electricity in Coulombs (C) but,                          Q = I x t .............................

Water of crystallization (WC) is the number of molecules of water present in one mole of a hydrated salt. Example, in iron (II) tetraoxosulphate (VI)-heptahydrate [FeSO4.7H2O], there are seven molecules of water attached to a molecule of FeSO4, that is its water of crystallization. Some other examples of salts with water of crystallization include: MgSO4.7H2O - Magnesium tetraoxosulphate(VI)-heptahydrate, (Epsom Salt) CaSO4.2H2O - Calcium tetraoxosulphate(VI)-dihydrate (Gypsum) Na2CO3.10H2O - Sodium trioxocarbonate(IV)-decahydrate (Washing Soda) CuSO4.5H2O - Copper (II) tetraoxosulphate(VI)-pentahydrate (Blue Vitriol) ZnSO4.7H2O - Zinc tetraoxosulphate(VI)-heptahydrate (White Vitriol) Cu(NO3)2.3H2O - Copper (II) trioxonitrate(V)-trihydrate From the above examples, it can be observed that each salt has a definite number of molecules of water of crystallization attached to it. Therefore, it can also be defined as the definite amount of water some substances chemically combine wi

The Gay-Lussac's Law of Combining Volumes states that when gases react, they do so in volumes, which are in simple ratio to one another and to the volume of the product, if any; provided temperature and pressure remain constant. It applies to only gases, which means that solid and liquid reactants and products are always ignored when applying this law. For instance, hydrogen burns in oxygen at 100°C to form steam according to the equation:        2H2(g) + O2(g) ---> 2H2O(g)          2mol      1mol           2mol          2vol        1vol            2vol          2cm^3    1cm^3        2cm^3 From the above, it implies that at 100°C, when water is in its gaseous state, 2 volumes of hydrogen gas (dm^3 or cm^3) will combine with 1 volume of oxygen gas to form 2 volumes of steam, to give a simple mole ratio of 2 : 1 : 2. Therefore, 50cm^3 of hydrogen will need 25cm^3 of oxygen to produce 50cm^3 of steam. Similarly, 15cm^3 of oxygen will require 30cm^3 of hydrogen to form 30

Mole concept is arguably the broadest topic in chemistry, as it cuts across every other branch of chemistry, as far as reactions are concerned. It is the foundation of calculations in chemistry.  Chemical reactions, expressed as equations, are ways of confirming the Law of Conservation of Mass, which states that matter is neither created nor destroyed, but is transformed from one form to another . This is also what was paraphrased in one of the postulations of Dalton's Atomic Theory, which is, atoms are neither created nor destroyed (during a chemical reaction), but are changed from one form to another . The above implies that if two substances A and B combine to give another substance C, i.e,              A  +  B  --->  C then, the total masses of A and B will equal the mass of C. In other words, all of A and B will be converted to C, assuming there is no loss. Meaning that if we know the masses of A and B, we can easily calculate what we should be expecting as C. Fo