Answer:
6.76*10^-4 , or 6.8*10^-4 if you consider sig figs
Step-by-step explanation:
This is a bit of a confusing question, since it incorrectly states that the acid disassociation constant is simply [H+][F-].
Ka = [H+][F-]/[HF] , so plugging in the values, we get
![K=([2.6*10^(-3)][2.6*10^(-3)])/([0.01])\\K=([2.6*10^(-3)]^2)/([0.01])\\K=0.000676=6.76*10^(-4)](https://img.qammunity.org/2023/formulas/chemistry/high-school/na1t2rhe0l44awn250g07fm7ah1hkg68qs.png)
If we were to use the equation in the question, Ka=[H+][F-], we would get the answer 6.76 * 10^-6 , which is not the Ka for HF