Solution, Suspension and Colloid | Is Matter around us pure? | Chemistry | Khan Academy
TLDRThis educational script delves into the categorization of mixtures, focusing on the differences between solutions, suspensions, and colloids. It explains that a solution, like salt water, is a homogeneous mixture with particles uniformly distributed and too small to scatter light. In contrast, heterogeneous mixtures such as chalk in water (suspension) and milk (colloid) have larger particles that do not uniformly distribute and can scatter light. The script clarifies that while colloids like milk have particles that remain suspended and do not settle, they are not dissolved like in a true solution, highlighting the Tyndall effect as a key characteristic.
Takeaways
- 🧪 Salt water is a homogeneous mixture where salt particles are evenly distributed and dissolved in water.
- 🔬 Solutions have particles smaller than 1 nm and do not scatter light, meaning they are uniform and cannot be separated by filtration.
- 🌌 The Tyndall effect is a characteristic of colloids where light scatters off the particles, making the light path visible.
- 📚 Heterogeneous mixtures are not uniform, with particles that can be seen and separated by filtration or settling.
- 📉 Chalk in water is a heterogeneous mixture where chalk particles settle at the bottom and can be filtered out.
- 🌟 Particles in a suspension are larger than 1000 nm and scatter light, making the path of light visible when shone through.
- 🍼 Milk is a colloid, a heterogeneous mixture with particles between 1 to 1000 nm that remain suspended and do not settle.
- 🚫 Colloidal particles are too small to settle and too large to dissolve completely, thus they cannot be separated by simple filtration.
- 🌈 The size of particles in different mixtures determines their classification: solutions (<1 nm), colloids (1-1000 nm), and suspensions (>1000 nm).
- 🔍 Observing the behavior of light and particles can help distinguish between solutions, suspensions, and colloids.
Q & A
What are the three types of mixtures discussed in the script?
-The three types of mixtures discussed are solutions, suspensions, and colloids.
How is a solution characterized according to the script?
-A solution is characterized as a homogeneous mixture where the solute is evenly distributed across the solvent, with particles being extremely small (0.01 to 1 nanometers), not settling down over time, and not scattering light.
What is an example of a solution given in the script?
-Salt water is given as an example of a solution, where salt (NaCl) is dissolved and uniformly distributed in water.
What are the key differences between a suspension and a solution?
-A suspension is a heterogeneous mixture where particles are not uniformly distributed, settle down over time, and can be separated by filtration. In contrast, a solution is homogeneous, with particles too small to settle or be separated by filtration.
Why is milk considered a heterogeneous mixture even though it appears uniform?
-Milk is considered a heterogeneous mixture because it contains fat droplets that are suspended but not dissolved in the liquid, with particle sizes between those found in solutions and suspensions (1 to 1000 nanometers).
What is the Tyndall effect mentioned in the script?
-The Tyndall effect is the scattering of light by particles in a colloid, making the path of the light visible when a beam, such as from a laser, passes through the mixture.
How does the script explain the particle size in colloids compared to solutions and suspensions?
-The script explains that the particle size in colloids is larger than in solutions (1 to 1000 nanometers) but smaller than in suspensions (greater than 1000 nanometers).
Why do particles in a suspension scatter light?
-Particles in a suspension scatter light because they are large enough (greater than 1000 nanometers) to interact with the light, causing it to scatter in multiple directions.
Can colloid particles be separated by filtration?
-No, colloid particles cannot be separated by filtration because they remain suspended and uniformly distributed throughout the mixture.
What property of colloids causes the Tyndall effect?
-The Tyndall effect in colloids is caused by the scattering of light by the colloid particles, which are of a size that allows them to interact with and scatter light.
How does the script describe the process of a solute dissolving in a solvent?
-The script describes the process as the solute particles, such as salt ions, taking up space between the solvent particles, like water molecules, resulting in an even distribution throughout the solution.
Outlines
🧪 Understanding Solutions, Suspensions, and Colloids
This paragraph introduces the concepts of solutions, suspensions, and colloids through the examination of three mixtures: salt water, chalk in water, and milk. The first mixture, salt water, is identified as a homogeneous solution where salt (NaCl) is uniformly dissolved among water molecules, with particles ranging from 0.01 to 1 nanometers in size. Such solutions do not allow for separation by filtration and do not scatter light. The paragraph then contrasts this with heterogeneous mixtures, like chalk in water and milk, setting the stage for a deeper exploration into the characteristics that differentiate solutions from suspensions and colloids.
📚 Characteristics of Suspensions and Colloids
The second paragraph delves into the specifics of suspensions and colloids. Chalk in water is used as an example of a suspension, characterized by its heterogeneous nature, with particles larger than 1000 nanometers that settle over time and can be separated by filtration. The chalk particles scatter light, which is observable when a laser is shone through the mixture. Moving on to colloids, milk is highlighted as an example. Despite being uniformly distributed, colloids are considered heterogeneous due to particle sizes ranging from 1 to 1000 nanometers. These particles are too small to settle and scatter light, demonstrating the Tyndall effect when a laser is used, thus they cannot be separated by filtration. The summary concludes by outlining the distinctions between these three types of mixtures.
Mindmap
Keywords
💡Homogeneous Mixture
💡Heterogeneous Mixture
💡Solution
💡Suspension
💡Colloid
💡Particle Size
💡Settling
💡Filtration
💡Scattering of Light
💡Tyndall Effect
💡Solute and Solvent
Highlights
Three mixtures are discussed: salt water, chalk in water, and milk.
Mixtures can be categorized as homogeneous or heterogeneous.
Salt water is a homogeneous mixture where salt is easily dissolved in water.
Chalk in water and milk are heterogeneous mixtures due to visible differences in composition.
Understanding the differences between solutions, suspensions, and colloids is crucial.
A solution is characterized by homogeneity, even distribution, and small particle size.
In a solution, particles do not settle and cannot be separated by filtration.
Particles in a solution do not scatter light, which is different from suspensions and colloids.
Suspensions are heterogeneous mixtures with particles greater than 1000 nanometers.
Chalk particles in water will settle and can be separated by filtration.
Suspension particles scatter light, which can be observed when light passes through.
Colloids are heterogeneous mixtures with particle sizes between 1 and 1000 nanometers.
In colloids, particles are uniformly distributed but not dissolved in the solvent.
Colloid particles remain suspended and do not separate on standing.
Milk is an example of a colloid with fat droplets suspended in liquid.
Colloid particles scatter light, a phenomenon known as the Tyndall effect.
The Tyndall effect is observed when a laser light is shone through a colloid like milk.
The properties of mixtures are essential for understanding their behavior and applications.
Transcripts
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