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 sperm cell (with 23 chromosomes from the father), fertilises an egg cell (with 23 chromosomes from the mother), the resulting fertilised egg has 46 chromosomes. Via cell division, it grows into a human, with 46 chromosomes in each of its body cells.