Topic 1 Diamond, Graphite and C60

Unit 6 Carbon and Carbon Oxides 

Topic 1

Diamond, graphite and C60

We know that the rich and colorful material world is composed of elements. For example, oxygen is composed of oxygen, hydrogen is composed of hydrogen, and water is composed of hydrogen and oxygen. Different elements make up different substances. So, in the material world, are there any examples of the same element forming different substances?

Studies have shown that transparent diamond, gray graphite and football-shaped C” are all simple substances composed of carbon elements, but because of their different atomic arrangements, there are obvious differences in their properties.

1. Elemental carbon

1. Diamond _

Pure diamond is a colorless, transparent, octahedral solid. Naturally collected diamonds can become dazzling decorations after careful grinding - diamonds.

Diamonds can be used to cut glass, cut marble, process hard metals, and be installed on the drill bits of drilling machines to drill hard rock formations

Stone etc. According to the use of diamond, it can be inferred that diamond must be very hard. In fact, it is the hardest substance that occurs naturally.

2.Graphite

Graphite is a dark gray metallic opaque fine scale solid. Graphite is soft and has a slippery feel. In addition, graphite also has excellent electrical conductivity.

In daily life and industrial and agricultural production, we often use charcoal, coke, activated carbon and carbon black, etc. The main component of these substances is also simple carbon, and their structure is similar to graphite.

Charcoal has a loose and porous structure, so it has adsorption capacity. This property of charcoal can be used to adsorb pigments in some food and industrial products, and it can also be used to adsorb odorous substances. The adsorption of activated carbon is stronger than that of charcoal. The canister in the gas mask uses activated carbon to absorb poisonous gas. In the sugar industry, activated carbon is also used to decolorize to make sugar. With the development of society, the scope of application of activated carbon continues to expand. For example, activated carbon is used in the deep purification of urban sewage, industrial wastewater and drinking water. People also use activated carbon to absorb harmful gases generated by decoration, etc. .

3. C60

Scientists have discovered that, in addition to diamond and graphite, there is a new type of carbon that exists in the form of simple substances. Among them, C60 was discovered earlier and has made important progress in research . .

per C60 . Molecules are made of 60 carbon atoms. The C60 molecule looks like a soccer ball (as shown in Figure 6-4) , and the C60 molecule in this football structure is very stable.

The discovery of the human beings understands a whole new carbon world. The unique structure of C60 determines that it has some special physical and chemical properties, which may be widely used in the fields of superconductivity, catalysis, materials, medicine and biology. At present, human research on C60 is deepening. China's scientific research institutions have made many achievements in the preparation and separation of C60 , the superconductivity of C60, and the structure of C60 , which have produced important influences in the world

2. Chemical properties of elemental carbon

The calligraphy and paintings written or drawn by ancient Chinese calligraphers and painters with ink (made of carbon black, etc.) can be preserved for a long time without changing color. Why is this?

At room temperature, carbon is chemically inactive. Carbon is not easily changed by sunlight or contact with air and moisture. What about the reactivity of carbon if the temperature rises?

1. Reaction of Carbon with Oxygen

Do you remember the phenomenon of charcoal burning in oxygen? When charcoal is fully burned, it reacts with oxygen to form carbon dioxide and releases a lot of heat.

When the carbon is not fully burned, carbon monoxide is generated and heat is released at the same time.

2. Reaction of carbon with certain oxides

The charcoal reacts with copper oxide to produce copper and carbon dioxide.

In this reaction, copper oxide loses oxygen and becomes elemental copper. The reaction in which the oxygen in this oxygen-containing compound is taken away is called a reduction reaction. Charcoal is a substance that reduces copper oxide to copper, and it has reducing properties. The reducibility of carbon can be used in the metallurgical industry. For example, coke can reduce iron from its oxide ore.

In addition, carbon can convert carbon dioxide into carbon monoxide at high temperatures.

After finishing this topic, you should know

1.Different elements can form different substances, and the same element can form different substances. Such as diamond, graphite and C60 are simple substances composed of carbon.

2.Charcoal and activated carbon are adsorptive.

3.Carbon is chemically stable at room temperature. At high temperatures, carbon is capable of reacting with many substances

4.The properties of a substance largely determine its use.