Question

question 13 (2 points)
what is present in human blood that ensures blood ph is maintained at approximately 7.4?
a buffer bicarbonate ions (hco₃⁻) and carbonic acid (h₂co₃)
hydrogen ions h+
salt molecules nacl

Explanation:

Buffers resist changes in pH. In human blood, the bicarbonate - carbonic acid buffer system helps maintain a pH of about 7.4. Hydrogen ions alone would not maintain a stable pH, and salt molecules like NaCl are not involved in pH - maintenance in this context.

Answer:

A. A buffer [bicarbonate ions ($HCO_3^-$) and carbonic acid ($H_2CO_3$)]