Each of these descriptions is a way of expressing the strength of a chemical solution. The strength of a solution can be expressed by Weight, Volume or both. It is easiest to describe each of these separately and illustrate them with an example.
V/V means Volume/Volume and is often used when you mix 2 liquids together. For example, a 50% v/v solution would be 50% of one solution and 50% of another – equal amounts of each in terms of Volume. Examples of these include Acetic Acid 50% v/v and Sulphuric Acid 50% v/v.
W/W means Weight/Weight. In a solution, it infers the percentage of substances by weight. For example, a Hydrochloric Acid 28% w/w solution means there are 280 grams of Hydrochloric Acid for every Kilogram of the solution (the remainder being water).
W/V means Weight/Volume . This is commonly used when a solid is dissolved in a liquid. For example, a 10% w/v solution means 100 grams of one substance is present for ever 1L of another. An example of this would be Barium Chloride 10% w/v – in this solution 100 grams of Barium Chloride is present for ever 1L of water.
If a solution is V/W it means Volume/Weight. This is the same as the example above but the other way around.
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