Consider the qualitative and quantitative composition of substances. We define its features for compounds of organic and inorganic origin.
What shows the qualitative composition of the substance
It demonstrates the types of atoms that are in the analyzed molecule. For example, water is formed by hydrogen and oxygen.
The sodium oxide molecule includes sodium and oxygen atoms. Sulfuric acid contains hydrogen, oxygen, and sulfur.
What the quantitative composition shows
It demonstrates the quantitative content of each element within a complex substance.
For example, in water there are two hydrogen atoms and one oxygen. Sulfuric acid consists of two hydrogens, one sulfur atom, four oxygen.
Phosphoric acid contains three hydrogen atoms, one phosphorus, and four oxygen atoms.
Organic substances also have a qualitative and quantitative composition of substances. For example, methane contains one carbon and four hydrogen.
Methods for determining the composition of a substance
The qualitative and quantitative composition of substances can be determined chemically. For example, when a molecule of a complex compound is decomposed, several molecules with a simpler composition are formed. So, when heating calcium carbonate, consisting of calcium, carbon, four oxygen atoms, you can get two oxides: calcium and carbon.
The complex substance and the compounds formed during the chemical decomposition can have different qualitative and quantitative composition of substances.
Simple and complex compounds can be of molecular as well as non-molecular composition.
The first group is in different state of aggregation. For example, sugar is a solid, water is liquid, and oxygen is gas.
Compounds of a non-molecular structure under solid conditions are in solid form. These include salts. In the process of heating, they melt, pass from a solid to a liquid state.
Composition Examples
"Describe the qualitative and quantitative composition of the following substances: sulfur oxide (4), sulfur oxide (6)." Such a task is typical in a school course of inorganic chemistry. In order to cope with it, you first need to make the formulas of the proposed compounds, using valencies or oxidation states.
The same chemical elements are present in both proposed oxides; therefore, their qualitative composition is the same. They include sulfur and oxygen atoms. But in quantitative terms, the results will differ.
The first compound contains two oxygen atoms, and the second contains six.
We carry out the following task: "Describe the qualitative and quantitative composition of H2S substances."
The hydrogen sulfide molecule consists of a sulfur atom and two hydrogens. The qualitative and quantitative composition of the substance H2S allows us to predict its chemical properties. Since hydrogen cation is present in the composition, hydrogen sulfide is able to exhibit oxidative properties. For example, similar characteristics are manifested in interaction with the active metal.
Information on the qualitative and quantitative composition of the substance is relevant for organic compounds. For example, knowing the quantitative content of components in a hydrocarbon molecule, one can determine its belonging to a certain class of substances.
Such information allows us to predict the chemical and physical characteristics of the analyzed hydrocarbon, to identify its specific properties.
For example, knowing that there are four carbon atoms and ten hydrogens in the composition, we can conclude that this substance belongs to the class of saturated (saturated) hydrocarbons having the general formula SpH2n + 2. All representatives of this homologous series are characterized by radical substitution reactions , as well as oxidation by atmospheric oxygen.
Conclusion
Any inorganic and organic substance has a certain quantitative and qualitative composition. Information is necessary to establish the physical and chemical properties of the analyzed inorganic compounds, and for organic substances, the composition allows you to establish class, to identify characteristic and specific chemical properties.