Question

make notes of ten main points of chapter- is matter around us pure?


i need accurate points please .....if the answer is favourable to me ...i will mark you as the brainliest ​

Answer 1

1. Purity

Pure substances

• Pure substances are elements or compounds.
• they have a fixed composition
• they cannot be broken down into simpler and entities by chemical or physical methods
• they are made up of only one kind of entity
• Example: diamond, carbon dioxide

2. Mixtures

• mixtures are formed by just mixing two or more pure substances such that each substance retains its own chemical identity.
• Types of mixtures — Homogeneous mixture: A mixture which has a uniform composition throughout is called homogeneous mixture or solution. Example: sugar in water, salt in water. Heterogeneous mixture: A mixture which contains physically distinct parts and has a non uniform composition is called heterogeneous mixture. Example: mixture of salt and iron filings, sand and sugar.

3. Solutions

A solution is a homogeneous mixture of two or more substances.

4. Alloys

Alloys are genius mixture of metals or a mixture of metal and and other element that cannot be separated into their components by physical methods.

Examples:

• Steel a combination of iron which is metal and carbon which is non metal
• brass a mixture of copper which is metal and Zinc which is also metal

5. solubility

solubility is a property showing the ability of a given substance which is the solute to dissolve in a solvent. it is measured in terms of the maximum amount of solute dissolved in a solvent at equilibrium. the resulting solution is called a saturated solution.

6. Suspensions

A suspension is a heterogeneous mixture in which the solute particles do not dissolve but remain suspended throughout the bulk of the medium.

• the solute particles settle down when a suspension is left undisturbed.
• they can be separated from the mixture by filtration.

7. Colloidal solutions

A Colloidal solution is a mixture in which the substances are regularly suspended in a fluid.

8. Evaporation

the process of conversion of water into water vapour is known as evaporation.

• it can be used to separate the volatile component (solvent) from its non volatile solute.

9. Centrifugation

centrifugation uses centrifugal force for the Separation of two liquids in a mixture. Here, a denser component of the mixture migrates away from the axis and lighter component migrates towards the axis.

10. Sublimation

sublimation is the transition of a substance from solid Phase to gaseous phase without changing into liquid phase

11. chromatography

chromatography is used to separate the different components in a liquid mixture.

12. distillation

distillation is a method for separating the components substances from liquid mixture by selective evaporation and condensation.

13. fractional distillation

fractional distillation is the separation of a mixture into its component parts of fractions by their melting points.

• this is the process of separation of chemical compounds by their boiling point.
• mixture is heated to a temperature at which one or more fractions will be vaporize.