summary of chapter 'is matter around us pure?'
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Summary of "IS MATTER AROUND US PURE?"
→ Matter is classified into two groups - Pure substance and Mixture.
→ A pure substance consists of only a single type of constituent particles.
→ The pure substances are of two types ob the basis of the nature of the constituent particles - Elements and Compounds.
→ An element is the basic form of matter that cannot be broken into a simpler substance by any chemical reaction.
→ Compounds are the substances that are composed of two or more elements, that are chemically combined with each other in a fixed proportion.
→ Mixtures are the substances that constituted by more than one kind of pure form.
→ The mixture is classified into types on the basis of nature of the
components - Homogeneous mixture and Heterogeneous mixture.
→ A homogeneous mixture is a mixture in which the particles are distributed uniformly and particles cannot be through naked eyes.
→ A heterogeneous mixture is a mixture in which the particles are not distributed uniformly and particles can be seen through naked eyes.
→ A solution is a homogeneous mixture.
→ There are two main components of a solution - Solute(Dissolved phase, usually present in lesser quantity) and Solvent(dissolving phase, usually present in large amount)
→ A Saturated solution is a solution in which no more amount of solvent can be dissolved at a given temperature.
→ Concentration of solution =
→ Concentration of solution =
→ A suspension is a heterogeneous mixture in which the solute particles do not dissolve, but remain suspended throughout the medium.
→ A colloidal is a mixture that is heterogeneous but appears to be homogeneous as the particles are uniformly distributed.
→ The scattering of light by colloidal particles is known as Tyndall effect.
→ Evaporation is a method which is used to separate volatile solvent from a non-volatile solute of a mixture.
→ Centrifugation is a method which is used to separate components having different densities.
→ Sublimation is the process in which the solid state changes directly into gaseous state or gaseous state changes directly into the solid state.
→ Chromatography is the technique used to separate the solutes that are dissolved in the same solvent.
→ Crystallization is the process that is used to separate pure substance in its crystal from a solution.
Matter is anything that occupies the space and has certain mass. Matter can be impure or pure. Impure matter is a mixture of many pure substances. Mixture contains more than one kind of pure form of matter in which their constituents do not lose their identity. Mixtures are of two types; homogeneous and heterogeneous mixture. Homogeneous mixture is a mixture that has a uniform composition throughout. A solution is a type of homogeneous mixture. Alloys are homogeneous mixtures of two or more metals or a metal and non-metals. Solution is a homogeneous mixture of two or more substances. Heterogeneous mixture does not have uniform composit tion throughout.
Suspension is a type of heterogeneous mixture. Colloid is a type heterogeneous mixture with a dispersed phase and a dispersion medium. Their particle size is more than the 1 nanometer but particles cannot be seen with naked eye. These particles can scatter light. This effect is called Tyndall effect. Components of colloids can be separated by centrifugation. Saturated solution is a solution, which has dissolved the maximum solute at particular temperature and no more solute, can be dissolved in solution at that temperature. The amount of the solute present in solution at given temperature is called its solubility.
The components of a mixture can be separated by various physical methods that include: evaporation, sublimation, separating funnel method etc. Evaporation is used to separate a volatile component from a non-volatile component. Sublimation is used to separate a sublimable volatile component from a non-sublimable component. Separating funnel method is used to separate two immiscible liquids from their mixture. Chromatography is used to separate components that are soluble in same solvent. Paper Chromatography is used to analyse the presence of different colour in a dye or in a black ink. Distillation is used to separate two miscible components of a mixture that have different boiling points. Crystallisation is used to separate a pure solid from its solution. In this method, the saturated solution of a substance is allowed to evaporate slowly. The liquid evaporates leaving behind the pure solid.
Pure substances consist of only one component with definite physical and chemical properties and a definite composition. Pure substances can be classified into elements and compounds. Elements are pure substances, which are made up of only one kind of atom and cannot be further reduced to simpler substances. Compounds are the substances made up of more than two types of elements combined together chemically in definite proportion by weight. Substances undergo chemical changes during the formation of compounds whereas during the formation of mixture, substances undergo physical change only. In physical Change, no change occurs in the chemical nature and composition of the substances. During chemical changes, change occurs in the chemical nature and composition of the substances.