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Is Matter Around us Pure? Complete Chapter🔥| CLASS 9th Science| NCERT covered | Prashant Kirad

Exphub 9th &10th・2 minutes read

Prashant introduces the chapter "The matter around us is pure" in Ninth Class, aiming to clarify concepts like colloid solutions, suspensions, and the Tyndall effect, emphasizing the importance of understanding concepts quickly for exams. He explains the properties of metals, nonmetals, metalloids, compounds, and mixtures, detailing their differences and the methods of separation, concluding with the distinction between physical and chemical changes and a quiz on the Tyndall effect.

Insights

Prashant aims to simplify complex scientific concepts like colloid solutions and suspensions, ensuring students understand without rote memorization, emphasizing quick comprehension for exams.
The distinction between compounds and mixtures is crucial, with compounds formed through chemical bonding having fixed proportions, unique properties, and separable only through chemical processes, while mixtures, whether homogeneous or heterogeneous, are physically separable and retain individual properties of their components.

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Recent questions

What is the Tyndall effect?
The Tyndall effect is the scattering of light by particles in a suspension solution.

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Summary

00:00

Chemistry Concepts: Pure Substances and Metals

Prashant introduces the next chapter of Ninth Class, focusing on "The matter around us is pure."
He plans to explain the chapter through experiments, acknowledging its potential boredom.
Prashant aims to clarify concepts like colloid solutions, suspensions, and the Tyndall effect.
He guarantees that after his lecture, there will be no need to memorize definitions.
Prashant emphasizes the importance of understanding concepts quickly for upcoming exams.
He assures students that with his guidance, they will grasp the material deeply and not miss any questions.
Prashant encourages students to follow his notes for success in exams.
He delves into the definition of pure substances in chemistry, emphasizing their consistent properties, inseparability, and definite composition.
Prashant distinguishes between elements and compounds, highlighting metals, nonmetals, and metalloids.
He explains the properties of metals, including luster, conductivity, color, sonorousness, ductility, and malleability, contrasting them with nonmetals.

11:53

"Metals, Non-Metals, and Metal Id"

Non-metals include oxygen and nitrogen, distinct from metals.
Metals and non-metals are separated by a poor metal category.
Metal id, an element with intermediate properties between metals and non-metals.
Examples like Boron, Silicon, and Germanium illustrate metal id.
Compounds are crucial, formed by combining two or more elements.
Fixed proportions are essential for compound formation.
Water serves as an example of a compound with a fixed proportion.
Compounds have three key properties, including fixed proportions.
Compounds exhibit unique properties distinct from their elements.
Compounds can only be separated through chemical processes.

23:44

Separating Mixtures: Physical vs. Chemical Properties

Heterogeneous mixtures can be separated physically, and water can be cleaned in a physical sense.
Examples of heterogeneous mixtures include elements, compounds, and mixtures.
The difference between compounds and mixtures lies in the properties formed by physical mixing and chemical combination.
Compounds are formed by chemical bonding, while mixtures are formed by physical mixing.
Mixtures can be homogenous or heterogeneous, with compounds always being homogeneous.
Mixtures can be separated by physical means, unlike compounds that cannot be separated.
When mixing substances, individual properties remain unchanged in mixtures, unlike compounds where properties change.
Mixtures do not form new substances and their properties depend on the components' consent.
Mixtures can be homogenous, heterogeneous, or colloidal, depending on particle size.
Solutions consist of solute and solvent, with solute being the component in smaller quantity and solvent in larger quantity.

36:52

Calculating Concentration of Solutions Using Formulas

Concentration of solutions can be determined using simple formulas.
The first formula is mass of solute divided by mass of solution * 100 for percentage concentration.
If the question provides the mass of solute and solution, apply the formula.
If the volume of the solution is given, use the formula volume of solute divided by volume of solution * 100.
Different numerical questions may require different formulas based on the information provided.
A question is presented where 36 grams of sodium chloride is dissolved in 100 grams of water at 293 Kelvin, requiring the concentration to be found.
The mass of solution is calculated by adding the mass of solute and solvent.
The concentration is then determined by applying the formula mass of solute divided by mass of solution * 100.
Another question involves a solution containing 60 grams of sugar in 480 grams of water, requiring the concentration to be calculated.
The concentration is found by dividing the mass of solute by the mass of solution and multiplying by 100.

49:16

"Understanding Solubility and Mixtures in Chemistry"

If 62 grams cost 100 grams, then 50 grams will cost 31 grams.
The question revolves around the amount of potassium needed in grams of water.
The concept of solubility is explained through saturated and unsaturated solutions.
A saturated solution does not allow additional solute, while an unsaturated solution can mix solute.
The concept of a collider solution is introduced as a heterogeneous mixture.
In a collider solution, small particles in a liquid are mixed to form a solution.
Disperse face and disperse medium are explained as types of solute and solvent in a collider solution.
A table is presented to differentiate between disperse face and disperse medium in various examples.
Examples like aerosol, foam, and emulsion are used to illustrate different types of mixtures.
The properties of a suspension, including being heterogeneous, visible particles, and scatter light, are detailed.

01:01:03

"Light Scattering and Chemical Changes Explained"

Mud water caused a problem with the lights, leading to a discussion on the scattering of light.
The Tyndall effect is explained as the scattering of light by particles in a suspension solution.
The Tyndall effect is demonstrated by passing light through a suspension solution, making the path of light visible.
Physical changes are distinguished from chemical changes, with examples like freezing water and burning paper.
The melting of ice, boiling of water, and rusting of iron are cited as examples of physical and chemical changes.
The burning of a candle is identified as a chemical change, while the melting of wax is a physical change.
The growth of a plant is considered a chemical change due to its irreversible nature.
Cooking food is described as a chemical change, while digestion of food is also categorized as a chemical change.
The freezing of water is noted as a physical change, contrasting with the burning of a candle as a chemical change.
A quiz on the Tyndall effect is conducted, with salt solution and starch solution identified as not showing the effect, while copper sulphate solution does.

01:12:51

"Pure Substances, Compound Reactions, and Composition"

Pure substances contain only one kind of particle, whether they are compounds or mixtures.
Pure substances have the same composition throughout, excluding all elements other than nickel.
When substances A and B react to form a third compound, the properties of the compound will differ from those of A and B.

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