I have a question about ph?

Question

if you use ph paper in a pur undiluted base will it work because doesnt it measure the amount of hydroxide moleculs which i thought were only caused when you dissolve a base in water...or am i thinking of something else

Answer 1

pH paper only works in the presence of moisture - you are quite right. But you should refer to the H+ or OH- ions that the paper responds to, not molecules.

NB there are not many pure, undiluted liquid bases around!

Answer 2

It won't. The paper has to be moist in order to detect. Furthermore, it has to be an alkali, a soluble base, where the hydroxide ions would dissolve in the paper. If it is an insoluble base, you would probably have to use phenolphthalein or methyl orange or universal indicator to test its pH.