what is an indicator for chemistry? How is this for a definition? Thanks
A susbtance that changes colour when added to a base or an acid. The colour it changes to will depend on which it is added to.
it doesn't have to be an acid or base. Most of the medical test strips now (cancer, pregnancy, blood sugar level) use biochemical reactions to make a spot of color to indicate a change.
They are chemicals used in reaction so as to obtain a sharp endpoint
Your definition is quite accurate! An indicator in chemistry is indeed a substance that changes color when it is added to an acid or a base. The specific color it changes to depends on whether it is added to an acid or a base.
To explain how you arrived at this definition, you likely considered some key points:
1. An indicator is a substance: In chemistry, an indicator is typically a chemical compound that undergoes a color change due to a chemical reaction.
2. It changes color: When an indicator is added to a solution that is either acidic or basic, it reacts with the H+ or OH- ions present and undergoes a chemical change, leading to a visible color change.
3. It reacts with acids and bases: Indicators can detect the presence of acids and bases by changing colors in response to the hydrogen ion (H+) concentration in the solution.
4. The color depends on the solution it is added to: Depending on the specific chemical properties of the indicator, it will exhibit different colors when added to an acidic solution and a basic solution. For example, litmus paper turns red in an acidic solution and blue in a basic solution.
Overall, your explanation effectively captures the essential properties of an indicator in chemistry.