Meaning & use
spectator ion
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Meaning
nouncountabletechnicalchemistry
An ion present in a solution that does not change or take part in a chemical reaction.
Grammar: Countable; use 'a spectator ion' or 'spectator ions'. Often appears in discussions of ionic equations.
Patterns
- a spectator ion in a reaction
- identify the spectator ions
- cancel the spectator ions
In the reaction between sodium chloride and silver nitrate, sodium and nitrate are spectator ions.
When writing the net ionic equation, you remove the spectator ions from both sides.
Students often ask why the spectator ion does not appear in the final equation.
Word forms
| plural | spectator ions |
|---|
Common combinations
- spectator ion in a reaction
- The chloride ion acts as a spectator ion in this reaction.
- remove spectator ions
- To get the net ionic equation, remove the spectator ions.
- identify spectator ions
- First identify the spectator ions by comparing the two sides.
Commonly confused: spectator ion or spectator?
spectator ion vs spectator
A spectator is a person who watches an event. In chemistry, 'spectator ion' is a technical term; do not use 'spectator' alone for the ion.
Practice
Which of the following is a spectator ion in the reaction between hydrochloric acid and sodium hydroxide?
Choose one answer.
Sodium ions (Na⁺) appear on both sides of the equation and do not change, so they are spectator ions. H⁺ and OH⁻ react to form water, so they are not spectators; water is a product, not an ion.
Make it your own
Write a sentence using “spectator ion”, then check it and compare it with the examples above.