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10 Cards in this Set
- Front
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A suspension is a mixture of fine particles suspended in a liquid. As time goes by, particles settle out of the medium in which they are suspended to form two distinct layers or phases. The particles are of a large size and can be filtered out. Since particles are not distributed evenly throughout the medium it is a heterogeneous mixture. |
Suspension |
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flavoured milk, paints, sand in water, salad dressing (oil in vinegar) and juice. |
examples of a suspension |
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A solution occurs when two substances completely mix with each other so that one part of the mixture is the same as any other part of the mixture- particles are uniformly distributed- the mixture is homogeneous. A solution consists of a solute completely dissolved in a solvent. cannot be filtered out. Solutions are clear and allow light to pass through without scattering and you cannot see the dissolved particles. |
Solutions |
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The most common solutions are- Solid in liquid (e.g.- sea water) Liquid in liquid (e.g.- alcohol in water) Gas in liquid (e.g.- fizzy soft drink) |
example of solution |
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- A colloid is a mixture in which the particles of one part of the mixture remain suspended among the particles - useful for storing/delivering a substance to its target surface. eg. Using sunscreen to spread the protective UV filters evenly over the skin also delivering drugs to a targeted site in the body. - The particles of a colloid are between those in a solution and a suspension - cannot be filtered out |
Colloid |
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Emulsion-A colloid of tiny liquid droplets suspended in another liquid. - Oil-in-water emulsion: droplets of oil dispersed in a water medium e.g.- cream, mayonnaise. - Water-in-oil emulsion: water droplets dispersed in an oil medium e.g.- butter. |
emulsion |
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the particles in a colloid are much larger than those in solution. when a beam shines through a colloid liquid the particles are large enough to cause light to scatter, called the tyndall effect. |
tyndell effect |
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- Foam- A foam is a colloid of gas particles dispersed in a liquid medium. Example- shaving foam, hair mousse, fire extinguisher. - Sol or Gel- A sol/gel is a solid particle dispersed in a liquid medium. Example- Paints, toothpaste, jelly.The use of a substance depends on its physical and chemical properties - Aerosol- A colloid of a solid or liquid particles dispersed in a gas medium. Example- smog, fly spray, aerosol deodorant, fog. Solid- Solid-A colloid of a solid particle dispersed in a solid medium. Example- opals, pearls, ruby glass. |
types of colloids |
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A surfactant is a substance which can reduce the surface tension of a liquid. |
surfactant |
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when detergent is added to water the surface tension of water is reduced and the wetting power is increased (absorbency) This is caused by the large difference in surface tension of each liquid as water molecules are polar but oil molecules are non-polar and do not dissolve in water. Water can only dissolve substances that are either polar or ionic (consisting of positive and negative ions). Surfactants have molecules that are able to attract molecules of both liquids which reduces the surface tension, thus oil and water will mix. |
how do surfactants work |
