The pH of H2PO4- depends on its role as an acid or a base in solution and the concentrations involved. Since the question does not specify the concentrations or context, it is best to answer based on the provided reference.
According to the provided reference, a phosphate buffer (H2PO4-/HPO42-) has a pH of 8.3. This buffer system utilizes the equilibrium between H2PO4- (dihydrogen phosphate) and HPO42- (hydrogen phosphate). The pH value of 8.3 reflects the buffer's capacity to resist changes in pH around this value.
Here's a breakdown:
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H2PO4- as a Buffer Component: H2PO4- is a key component of phosphate buffers used in biological and chemical systems. Its ability to both donate and accept protons contributes to maintaining a stable pH.
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pH and Buffer Systems: Buffer solutions are designed to maintain a relatively stable pH when small amounts of acid or base are added. The H2PO4-/HPO42- buffer is effective around pH 8.3.
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Example: In biological systems, phosphate buffers help maintain the pH of intracellular and extracellular fluids.
