I was going over past exams and I came across problem #36 on the 2018 USNCO locals, which stumped me when I came across it. I knew acid/base equilibrium problems were one of my weak spots and I spent lot of time refining that section (I use Atkins 7th edition) but when I checked the solution for #36, it involved a really long multi-step solution where the molar solubility (MS) was assigned to a variable and you had to use several relations and equations to solve for the ratio between the final MS and the initial MS. Are there any tips for how to approach longer problems such as these, and how to recognize when to use these approaches? Are problems like these a trend or an exception in the competitions?
Thanks for the help!
*Link to #36 Solution: https://docs.google.com/document/d/1AEG2u8bZ_Buv4rBzwDTaTSKZJ6urx0LKs038S87Zs9U/edit