Calculate the ionic strength of 100mM solution of Mg3(PO4)2 in 10 mM acetic buffer (CH3COONa)
To calculate the ionic strength of a solution, you need to consider the concentrations and charges of all the ions present.
In this case, we have a 100 mM solution of Mg3(PO4)2 and a 10 mM solution of acetic buffer (CH3COONa). Let's break it down step by step:
1. Determine the ions present:
- Mg3(PO4)2 will dissociate into 3 Mg2+ ions and 2 PO4^3- ions.
- CH3COONa will dissociate into CH3COO^- ions and Na+ ions.
2. Determine the concentration and charge of each ion:
- In a 100 mM solution of Mg3(PO4)2, we have 3 * 100 mM = 300 mM of Mg2+ ions and 2 * 100 mM = 200 mM of PO4^3- ions.
- In a 10 mM solution of acetic buffer (CH3COONa), we have 10 mM of CH3COO^- ions and 10 mM of Na+ ions.
3. Calculate the ionic strength for each ion:
- For each ion, we take the sum of the concentration multiplied by the square of the charge.
- For Mg2+: (300 mM * 2^2) = 1200 mM^2
- For PO4^3-: (200 mM * 3^2) = 1800 mM^2
- For CH3COO^-: (10 mM * (-1)^2) = 10 mM^2
- For Na+: (10 mM * 1^2) = 10 mM^2
4. Sum up the individual ionic strengths:
- Total ionic strength = 1200 mM^2 + 1800 mM^2 + 10 mM^2 + 10 mM^2 = 3020 mM^2
Therefore, the ionic strength of the solution is 3020 mM^2.