The acidity of a solution is typically measured by pH. A pH of 7 is neutral. A pH below 7 is acidic, and a pH above 7 is basic, or alkalotic. Normal blood pH is 7.4. Having acid in the blood means that the pH is below 7.4, and excessive protons may be found in the blood.
The number of chromosomes in the secondary spermatocyte are 23 but each chromosome having two chromatids, while the chromosomes in the spermatid are also 23 but each chromosome is made up of one chromatid.
When a mature sperm cells ultimately unites with a mature egg (which also has only one of the pair for each of the 23 chromosomes) the resulting fertilized egg then has 23 pairs of chromosomes (one of each pair from the father and one of each pair from the mother).