Answer:
1.15 hours
Explanation:
If they are going 100 kilometers an hour, and they need to go 115 k, then do 115/100 which is 1.15 which is the time
"The other halogens are not as electronegative and so other hydrogen halides cannot form hydrogen bonds between molecules. Only London Forces are formed. - Therefore more energy is required to break the intermolecular forces in HF than the other hydrogen halides and so it has a higher boiling point."
not a hack link, just stating where i got your answer from! -
https://www.mytutor.co.uk/answers/17558/A-Level/Chemistry/Explain-the-unusually-high-boiling-point-of-HF/
One possible answer could be that a chemical reaction has occurred.
I think 8 or 6 im not sure