Narrow range pH Indicator paper

[judygee]

Any of you good folk had trouble when using narrow range pH indicator paper? Does it go "off" if stored for a long while? Last year the chemistry teacher complained about the paper "not working", so we got some new booklets however these are "not working" this year!!!! Is there a trick to its storage and use? We are not having any trouble with the full range papers! Anyone help? Looking forward to your response. Judy.

[Robb]

Hi All,

There is a problem within itself when it comes to narrow range indicators and that is, they are very susceptible to the slightest contamination if this falls within the range. This obviously renders the whole thing useless.

Narrow range indicators can also change in transit if packaging is not suffice or also during the packing process.

I have never used Narrow Range, because of difficulties in storage...

To preserve it better, keep this in a desiccator. This will at least protect it.

I hope this helps....

Cheers,

Robb.....

[Ocker]

I can't keep blue Litmus paper in cupboard, so I store in beaker set into larger beaker with small amount of Ammonia solution and Gladwrap over the top

[RosalieM]

Does anyone know if a pH paper exists for the range pH 3-5? If so, what is it called and where would I get it?

[judygee]

Dear Rosalie - Whatman produce a narrow range pH paper (pH 4 - 6) Also Science Supply Australia (pH 3 - 6) However please refer to previous posts, I have had a great deal of difficulty keeping my narrow range papers "viable" We haven't had any success the last couple of years and I now have them in the dessicator as Rob suggested, sooo we shall see!! Hope that helps. Judy