Chemical reactions with carbidesthey are very simple and do not have a wide variety of reaction processes. To know and determine the reaction products of carbides, substances that react easily with water, it is necessary to know the carbide that is being used.
You carbides they are, in general, binary substances that present carbon as the most electronegative chemical element. The chemical elements that make up carbides are low electronegativity metals and metals.
There are two types of carbides:
Carbide in which carbon has a -4 charge (C-4), called methane;
Carbide in which carbon has a charge of -2 (C2-2), called acetylide.
To know how to recognize a methanide or an acetylide, it is enough to analyze the formula of the carbide used. If in the formula the carbide has the number two as a numerical index, it means that it is an acetylide. See some examples:
CaC2: the index 2 on carbon indicates that we have an acetylide;
Al4Ç3: the fact that we don't have the index 2 on carbon indicates that we have a methane.
Thus, if we know how to recognize the type of carbide we are dealing with, we can know the products that it will originate when reacting with water. If we have a methane, it will always produce a inorganic base and methane gas. See some examples:
Aluminum methane, when reacting with water, produces aluminum hydroxide base and methane gas.
1 Al4Ç3 + 12 H2O → 4 Al(OH)3 + 3 CH4
Iron III methane, when reacting with water, produces iron III hydroxide base and methane gas.
1 Fe4Ç3 + 12 H2O → 4 Fe(OH)3 + 3 CH4
When we use the acetylide in water, the chemical reaction of this carbide will always give rise to an inorganic base and acetylene gas (C2H2).
Calcium acetylide, when reacting with water, produces calcium hydroxide base and acetylene gas.
1 CaC2 + 2 H2O → 1 Ca (OH)2 + 1 C2H2
Zinc acetylide, when reacting with water, produces zinc hydroxide base and acetylene gas.
1 ZnC2 + 2 H2O → 1 Zn (OH)2 + 1 C2H2
By Me. Diogo Lopes Dias
Source: Brazil School - https://brasilescola.uol.com.br/quimica/reacoes-quimicas-com-carbetos.htm
