What are graphite and diamond made of
Graphite and diamond sound nothing to do, but in fact they are composed of the same element, both belong to the carbon element of carbon, the chemical formula of the two are C, the chemical properties are basically the same, is composed of the same element of carbon allotype.
Second, what is the difference between graphite and diamond
Graphite and diamond are allotropes, although both are composed of carbon, but they are not the same substance, there are certain differences in many aspects, including:
1. Different crystal structure
Graphite is a hexagonal crystal structure, and it is a molecular crystal, natural graphite will have a scale-like texture. Diamond is a regular octagonal structure, which belongs to atomic crystals, which are tetrahedral with each other.
2, the appearance of different colors
Graphite is usually dark gray, and its surface will emit a metallic luster. Diamond is more color, it has colorless, but also translucent, and fully transparent, there are black, but colorless is the best, translucent second, black worse.
3. Different physical and chemical characteristics
The hardness of graphite is lower than diamond, which is known as the hardest object in nature, so graphite is relatively soft. However, in terms of chemical properties, the melting point of graphite is higher than that of diamond, so it is more heat and high temperature resistance and corrosion resistance.
4, suitable for different purposes
Because of its soft texture but high melting point, graphite is more suitable for high temperature lubricants, pen refill, battery electrodes, chemical pipelines and so on. Because of its high hardness, diamond is suitable for making drill bits, glass knives, decorations and so on.
Third, graphite and diamond which is more stable
Graphite is more stable at room temperature, and the chemical properties of diamond are more stable than graphite under high pressure conditions.
Under normal temperature conditions, the chemical stability of diamond is worse than that of graphite, because every two carbon atoms are single bonds, and there is a large π bond between six carbon atoms in a single layer of graphite, which makes the carbon-carbon bond energy of graphite higher, and the higher the bond energy, the more stable. At the same time, the Gibbs free energy of diamond conversion to graphite in the standard state can be calculated to get a negative value, indicating that diamond will spontaneously tend to be converted to graphite under normal pressure.
Although it is true that the chemical properties of the bond energy theory are more stable, any chemical reaction will tend to a more stable state, and double-layer graphite will spontaneously transform into a diamond structure under high pressure, so the chemical properties of diamond are more stable than graphite under high pressure conditions.