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.
Now, note that after the final meiotic split (which produced 4 cells in total), each of the final gametocytes has 23 individual chromosomes. 22 of those chromosomes are the halves of the autosomal chromosome pairs, and one of the chromosomes is either an X or a Y chromosome.