Acid-base equilibria
Read our general notes on Risk Assessment
Is there another suitable indicator or better indicator to replace methyl orange titrating a strong acid with weak base? I want to know because I found it hard to determine a end point during a titration practical using methyl orange.
There are several alternatives. Look at Table 6.6 in the Nuffield Book of Data and pick an indicator which changes colour somewhere between pH 3 and 6. Of course, it will depend on what your school or college has available. Number 5 in the list, methyl orange-xylene cyanol, is usually called 'screened methyl orange' and was developed because its colour change is sharper than that of methyl orange, so it would be a good choice. Notice that its colours are completely different from those of methyl orange itself.
Bromophenol blue or methyl red would be other safe choices.
Jenkin
Risk assessment
Before attempting any practical work based on the advice and suggestions on this website, you must do the following. Identify any hazards, assess the risks from these hazards, and then decide appropriate control measures to reduce the risks. You must have these approved by those in authority in your school or college laboratory. Do not rely on what is said on this website.
For further guidance see our tutorial on Risk Assessment.
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updated: 21 August 2003
