How many milliequivalents of Na\(^+\) are contained in a 15 mL volume of the following buffer?

Buffer Composition:
- Na\(_2\)HPO\(_4\cdot 7\)H\(_2\)O: 180 g
- NaH\(_2\)PO\(_4\cdot\)H\(_2\)O: 480 g
- Purified water a.d.: 180 g

Choose the correct option:
a) 72.3 mEq
b) 4.82 mEq
c) 89.33 mEq
d) 3.478 mEq

The milliequivalents of Na+ in a 15-mL volume of a buffer made up of Na2HPO4.7H2O and NaH2PO4.H2O, depends on the exact compositions of the buffer. Each salt contributes a certain amount of Na+ per mole, hence the milliequivalents of Na+ can be determined when the buffer composition is known.

Explanation:

The question is to determine the number of milliequivalents (mEq) of Na+ contained in a 15-mL volume of a buffer made up of Na2HPO4.7H2O and NaH2PO4.H2O. The milliequivalent of Na+ is inherent to the number of grams of each salt because each mole of Na2HPO4.7H2O gives 2 milliequivalents of Na+ and each mole of NaH2PO4.H2O gives 1 milliequivalent of Na+. It's important to note that the molar mass of Na2HPO4.7H2O is roughly 268 g/mol and of NaH2PO4.H2O is approximately 138 g/mol. Using these values, the moles of each salt can be calculated and then the milliequivalents of Na+. Therefore, the answer is dependent on the precise compositions of the buffer which is not specified.

Learn more about Milliequivalents of Na+ here:

https://brainly.com/question/31920642

#SPJ11