Illustrated · 1 min
Importance of Solubility Rules
In aqueous solutions, salts are solvated as ions. When two salt solutions are mixed, the ions of one salt can interact with ions of the other salt. Sometimes, two ions interact that form an insoluble salt.
Solubility rules describe the solubility of different salts in water. These rules are helpful for:
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Identifying unknown salts
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Predicting solubility
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Preventing or creating precipitation
Solubility Rules
There are some solubility rules, but many of these have exceptions. It is important to review and know these rules when investigating solubility.
These rules can be categorized by:
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Soluble - 1g of solid will dissolve in 100mL of water.
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Low Solubility - 0.1-1g of solid will dissolve in 100mL of water.
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Insoluble - less than 0.1g will dissolve in 100mL of water.

This chart includes to rules of solubility in water of specified ions.
Image source: By Cassie Gates

This chart includes the rules for low solubility substances.
Image Source: By Cassie Gates

This chart includes the rules for insoluble compounds.
Image source: By Cassie Gates
