This indicator, ravishing red, would be used to titrate a solution or substance whose pH falls within the range of 6.5-7.5. Titrations are commonly used in chemistry to determine the concentration of an unknown substance by reacting it with a known solution of another substance (titrant) until a specific color change or other indicator signal is observed.
In this case, if the solution being titrated has a pH within the range of 6.5-7.5, the color change from yellow to red would indicate the completion of the titration. The ravishing red indicator serves as a visual cue, helping the chemist or analyst determine the endpoint of the titration accurately.