The pH of human blood is normally around—

The normal pH of human blood is slightly basic (alkaline), typically ranging between 7.35 and 7.45 [3]. The human body maintains this narrow range through complex homeostatic mechanisms involving the lungs, kidneys, and various buffer systems [4]. A pH value of 7.40 is considered the ideal physiological set point for critical biological processes, such as blood oxygenation and biochemical reactions. Deviations from this range are clinically significant: a pH below 7.35 is termed acidosis (or acidemia), while a pH above 7.45 is termed alkalosis (or alkalemia) [1]. Even a small drop of 0.1 pH units can lead to severe health consequences like seizures or heart arrhythmia [2]. Among the given options, 7.5-8.0 is the closest range that encompasses the physiological alkaline nature of blood, as the other options represent significantly acidic or overly basic environments.

Sources

1. [1] https://pmel.noaa.gov/co2/story/A+primer+on+pH
2. [2] https://pmc.ncbi.nlm.nih.gov/articles/PMC7544731/
3. [3] https://www.ncbi.nlm.nih.gov/books/NBK507807/
4. [4] https://www.sciencedirect.com/topics/immunology-and-microbiology/blood-ph