Ratio Strength
Ratio Strength is another expression used for describing the concentration of a solution or a mixture. In expressing ratio strength it is customary to have the first figure as 1, followed by a colon and then another number, e.g, 1:100. The following definitions are helpful when working with a ratio strength preparations:
Solids in liquids: 1 g of constituent in X ml of solution or liquid preparation.
Liquids in liquids: 1 ml of constituent in X ml of solution or liquid preparation.
Solids in solids: 1 gram of constituent in X g of mixture.
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Solved Problem: Express 5% w/w as a ratio strength. Approach: convert the percentage strength to a ratio and simplify. $$ {5 \% \over 100 \%} = {1 \ part \over x \ parts}$$ Answer: 1 : 20 |
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Solved Problem: Express 1:200 as a percentage strength. Approach: Set up a ratio from the ratio strength to a percentage. $$ {1 \ part \over 200 \ parts} = {x \% \over 100 \%}$$ Answer: 0.5% |