Hello, Nice to meet you everyone~!

I have a question about ionic strength.

I am not familiar with chemistry (I am a mechanical engineering student).

I am using gold colloid and the gold colloid is suspended in HAuCl4 solution.

And I will mix gold colloid (suspended in HAuCl4 solution) with DI-water to adjust number concentration, and I have to keep the solution pH10 and change the ionic strength of the diluted gold particle solution like 0.001, 0.01, 0.1, and 0.2 by adding NaCl.

How do I calculate current ionic strength before adjusting the ionic strength? for example, MW for HAuCl4 is 340 g/mol. and the product information says it is 0.01 % solution, so in 1 g (1 ml), the mol of HAuCl4 is 0.01/340, which is 2.94E-5. Therefore, if I dilute this 1 g of HAuCl4 solution with 99 ml of Di-water. Now, HAuCl4 has 2.94E-7 mol in 1 g of this diluted solution.

After this process, I am not sure about how to calculate the initial ionic strength for the solution.

Thanks sincerely!