A chemical combination occurs if two or more chemicals are combined so that each has its own unique chemical identity. These chemical bonds among the components aren’t broken or formed.
Be aware that, even though the chemical characteristics of ingredients haven’t changed, the mixture could exhibit new physical properties like melting point and boiling point. In the example above, mixing water and alcohol results in the mixture having an increased boiling point and a higher melting temperature than alcohol (lower boiling point and a higher temperature than the boiling point of water).
So, let’s start by understanding what exactly mixtures are.
What is a Mixture?
A mixture is a physical combination comprising two or three substances that aren’t chemically linked. For instance, salt and water are two distinct substances that, when combined, form a mixture. Salt is a distinct substance that, when combined, form an amalgamation – seawater.
Mixtures are compounds and elements that do not undergo chemical changes, which means that each element remains true to its properties as it is its individual substance.
This is because mixtures can be broken down into their constituents, transforming into distinct substances again without a chemical reaction. This is done by using specific techniques such as Distillation and filtration.
What are Common Examples of Mixtures?
Defining mixtures as more than items that are combined not chemically but physically are, here we offer some examples:
- Sugar and Flour may be mixed to form a mixture.
- A box of toys
- Cement (sand, water, gravel)
- Sand and water
- Smoke is a mixture of gases and minutes solid particles.
- Salt and Marble may be combined to form a mixture.
- Sugar and water form sweetwater, which is a mixture.
Mixtures can be either heterogeneous (elements of the mixture are readily separated from one another) or homogeneous (mixture stays uniform throughout the mix).
Let’s consider the case of iron filings and Sulphur powder. If they are mixed, the iron filings in the mixture can be extracted with the help of a magnet.
This is because the chemical characteristics of the mix are not altered. If we make a mix of iron and sulfur, the iron filings are not removed using the help of a magnet.
Instead, a brand new solid metal substance is made. The reason for this is that these atoms are rearranged and then bonded. In this case, there is a chemical change that has taken place, which is not a combination of physical elements.
What are the Features of a Mixture?
Well, mixtures are different from chemical compounds due to:
- We can separate the components in a mix by physical processes like filtration, freezing, or Distillation.
- There is minimal or no energy exchange when a mixture is formed.
- Mixtures can have a variety of compositions, as do compounds, while mixtures have a fixed formula.
- When they mix, the individual elements retain their properties, but their properties change when they mix.
In simple words, Mixtures are a physical blend of various components and not chemicals. Their atoms have not been altered, and the mixture’s ingredients have their unique identity and characteristics.
They differ from compounds; they are combinations of which the atoms are changed so that we can’t separate them.
What’s The Difference Between Mixtures and Compounds?
Mixtures possess different properties than compounds:
- In a mixture, the different substances don’t have a chemical bond and thus retain their distinct property. In compounds, various substances are chemically blended, and their properties change to form new compounds.
- The quantity of each element in a mix can be different; however, a compound has a specific composition, which means that the quantity of each component within it can’t be altered.
- While the components in a mixture are easily separated, chemical reactions are the only way to divide a compound into its constituent parts.
Examples of Compounds
- Sodium Chloride
- Magnesium Oxide
- Carbon Dioxide
How can Mixtures be Separated?
There are a variety of methods to differentiate mixtures made from two to more distinct materials. Here’s a quick listing of some techniques that students in KS2 are taught about before they depart from primary school. It’s possible to try some at your home!
Condensation and Evaporation
This process is identical to Simple Distillation, but it’s slightly more complex. If you’d like to separate both solid and liquid substances from the mixture after they’re separated from each other, then you can freeze and capture the vapour of water as it is released from the solution. Once the water vapour has been refrigerated, it transforms into water once again.
It means you can preserve both parts of the original mixture. It usually requires an instrument called a condenser; however, the one you use might not be able to work at home!
Evaporation (also called simple Distillation)
This technique is ideal for separating a mixture of the liquid (usually water) and a solid, which is dissolved within the fluid. When the solution is heated to boiling and letting the water evaporate, it will melt away, leaving the solid dissolved within it.
This technique is ideal for the separation of solids with different dimensions. Smaller objects will go effortlessly through the holes of the sieve, but larger objects will remain behind.
This method is based on a mixture of two or more liquids like water and oil. Pour the mixture into one container. Then let the liquids settle. When the liquids settle, they should make two separate layers. You will remove the top layer, separating the liquids.
This technique is best used when you have a lot of solid metal objects. If you use a magnet to pass it over numerous metal objects separating magnetic items becomes possible because they’re drawn to the magnet!
Filtering. This technique is used to separate insoluble solids and liquids, like the mixture of water and sand. When you pour the mixture over filter paper, the liquid will flow through. However, the solid will remain in a state of impossibility to pass through the filter paper.
While concluding, let’s understand what’s not a mixture! Just because two chemicals mix, don’t expect to get a mixture! The identity of the reactant changes when a chemical reaction occurs. This isn’t a mixture. For example, combining an acid with a base doesn’t produce a mixture.
Therefore, now you can understand what exactly is a mixture and what is not.