Chapter-2 Is matter around us pure Extra Questions

Explanation:

 Any pure element or pure compound is included in the definition of a substance, which is an object with a distinct composition and properties. A substance cannot physically be split. The structure and features of a pure material are well-defined. They are made up of things like sugar and iron.

Explanation:

Homogeneous mixture: Whether a mixture is solid, liquid, or gaseous, homogeneous mixtures have the same ratios of their component constituents throughout a particular sample. Its composition stays the same throughout. There is just one observable phase of substance in a homogeneous mixture.

Heterogeneous mixture: A mixture is referred to as heterogeneous if its constituent parts are not dispersed equally. A single-phase is, by definition, a pure substance or homogenous combination. A heterogeneous mixture has two or more phases.

Due to their equal dispersion, the particles are readily identifiable with the unaided eye and under a microscope.

Explanation:

NaCl solute mass is 36 g.

Solvent mass (H2O): 100 g

NaCl and water have a mass of 136 g.

NiConcentration is determined by multiplying the mass of the solute by the mass of the solution by 100.

Concentration  36/136 times 100, or 26.47%.

Hence, the solution’s concentration is 26.47%.

Explanation:

The solution reveals that kerosene and gasoline are miscible and that there is a significant

difference—more than 25 degrees Celsius—between their boiling temperatures. As a result, a distillation procedure makes it simple to tell them apart.

Because to the greater than 25 degree difference in their boiling temperatures, kerosene and gasoline can be separated by distillation. The mixture of kerosene and gasoline will be put into a very hot distillation flask. Petrol will vaporise and create vapours first as the mixture’s temperature rises because it has a lower boiling point. A condenser condenses gasoline vapours, which are then collected via the condenser output. Higher boiling point kerosene will condense in the distillation flask and be left behind.

If the difference between the boiling points of two liquids is not considerable, a straightforward distillation process cannot be used to separate them since their vapours will form within the same temperature range. These liquids are separated using fractional distillation by passing the vapours through a fractionating column prior to condensation.

Explanation:

a ) Butter and curd are separated using the centrifuge technique. The density principle controls the procedure.

b ) The straightforward evaporation method can be used to remove salt from saltwater. Salt is produced during distillation, which causes water to evaporate and leave behind solid salt.

c ) As camphor doesn’t go through a liquid phase during the phase transition, sublimation can be employed to separate camphor from salt.

Explanation:

To extract solids from a liquid solution, crystallisation is a method utilised. Although it is related to precipitation, this method produces the precipitate in the form of crystals that are incredibly pure. To cleanse impure material, one can use the crystallisation principle.

Explanation:

The categories based on pure chemicals and combinations are listed below:

Pure substance:

• Water 

• Salt 

• Iron 

• Diamond

Mixture:

• Soil 

• Salad 

• Air 

• Steel

Explanation:

a) During the process of evaporation, sodium chloride in its solution can be separated in water.

b) Ammonium chloride supports sublimation, hence the approach is appropriate.

c) Small metal fragments in an automobile’s engine oil can be manually filtered out.

d) The fine separation of different pigments from an extract of flower petals can be accomplished using chromatography.

Explanation:

(a)It is possible to use centrifugation to separate butter from curd. It is based on the idea of density disparity.

(b)Using a funnel to separate oil from water, which are two immiscible liquids with different densities, can be an efficient technique.

(c)Tea leaves and tea can be manually separated using basic filtration techniques.

(d)Iron pins have a strong magnetic quality, which can be a crucial factor to take into account, and can be used to separate from sand either manually or with the aid of magnets.
(e)I There is a difference in their bulk, which makes husk and wheat distinct from one another. When subjected to even a modest amount of wind energy, the travelling distance exhibits an amazing variety. Hence, the sedimentation/winnowing process can be used to separate them.

(f)Sand or small mud particles tend to sink to the bottom of a body of water because water is denser there when it is not disturbed. Water may be separated from tiny mud particles through the sedimentation/decantation process since the approach is based on tilting out clear water.

Explanation:

a) Pour one cup of milk, the solvent, into a container and boil it up.

b) To the boiling milk, which serves as a solute, add tea powder or tea leaves. Keep up the heating.

c) While the milk is still boiling, it is possible to see that the solute—in this case, the tea powder—remains insoluble.

d) Now, while stirring, add some sugar to the boiling solution.

e) Although sugar is a solute, the solvent makes it soluble.

f) With constant swirling, the sugar entirely dissolves and the tea solution reaches saturation.

g) After the tea solution has sufficiently boiled and the raw tea leaf smell has disappeared, remove it from the heat and filter or strain it to separate the tea solution from the tea powder. When the solute (sugar) and the solvent (essential milk solution) pass through the filter medium and are collected as the filtrate, the insoluble tea powder remains as a residue.