What is the normal pH range of human blood?

Calculate the pOH of $0.01$ M monobasic acid that is completely dissociated, at $298$ K.

A weak monobasic acid is $4\%$ dissociated in $0.05$ M solution. What is percent dissociation in $0.1$ M solution ?

What is the difference in oxidation number of nitrogen when nitric acid is converted into nitrous oxide ?