General Awareness play a vital role in all Examination. we can expect Questions from different Topics.In Banking and other competitive exams like RRB, CDS, LIC AO, RBI, SSC, UPSC, FCI, UIIC, OICL, SBI Clerks and PO the questions on Mixture and its type are being asked. Here we have given chemistry study notes on Mixture and its type for SSC CGL Examinations 2019-20 & other examination. Candidates those who are all preparing for the Examination can use this study material.
What is a Mixture
A mixture is formed of little bits of one or more substances mixed together. Usually, the parts can be separated from each other by physical means, because it does not involve any chemical reactions or bonds.
Examples of Mixtures
Crude oil: A mixture of organic compounds (mainly hydrocarbons)
Seawater: A mixture of various salt and water.
Air: a mixture of various gases like oxygen, carbon dioxide, nitrogen, argon, neon, etc.
Ink: A mixture of coloured dyes.
Gunpowder: A mixture of sulfur, potassium nitrate and carbon.
General Properties of Mixtures
Mixtures are made up of two or more substances which are not chemically combined with each other. The properties of mixtures are listed below.
- The components of a mixture each keep their original properties.
- The separation of components can be easily done.
- The proportion of the components is variable.
Types of Mixtures
A mixture can involve two or more substances of the same phase or different phases. For example you can mix water and sand (liquid and solid), sugar and salt (solid and solid), water and oil (liquid and liquid) or nitrogen and oxygen (gas and gas). Clearly, mixtures can vary a lot and can be
Mixtures involve mixing substances, so let us first be clear what a homogenous substance is. When a sample of matter has the same composition throughout, we call that substance a homogeneous substance. A cup of water will have the same chemical composition throughout (symbol for water). That makes it a homogeneous substance. A piece of gold will also have the same chemical composition, making it a homogenous substance. Homogeneous Mixtures behave in a similar way — the substance formed appear to have the same chemical composition. Alloys and Solutions are Homogeneous mixtures.
- All solutions are examples of a homogeneous mixture.
- The particles in such a case are less the one nanometer.
- They do not show a Tyndall effect.
- You cannot differentiate the boundaries of particles.
- You cannot separate the constituent particles here using centrifugation or decantation.
- Alloys are examples of a solution.
A mixture can also result in two or more phases clearly separated by boundaries. Very often, the separation can be clearly seen by the eye. A heterogeneous mixture is one that does not have uniform properties and composition. Take a look at a bowl of cereal with nuts. A spoon full will surely have a different number of nuts than a second spoonful taken at random. Another example—take some sea-sand into your palms. Look at it closely and you will notice that some sand particles are bigger than others, and the colors of some particles may be different too.
Heterogeneous mixtures include colloids, emulsions or suspension
- Most of the mixtures are heterogeneous except solutions and alloys.
- The constituent particles are present uniformly here.
- You can identify the components easily.
- Generally, two or more phases are present in a heterogeneous mixture.
- The size of the particles here is between one nanometer and one micrometer.
- They show a Tyndall effect.