Explanation:
According to Boyle's law, pressure of a gas is inversely proportional to its volume at constant temperature and moles.
Mathematically, P = 
where, k = proportionality constant
Also, formula for initial pressure and volume is as follows.

or, 
=
= 30 atm L
Now, we will calculate the value of
as follows.

= 
= 30 atm L
Hence, as
this means that it signifies that gas obeys boyle's law.
The ph would most likely be 7
hope this helps
There are other ions that make acidic and basic solutions, but we won't be talking about them here. That pH scale we talked about is actually a measure of the number of H + ions in a solution. If there are a lot of H + ions, the pH is very low.
Hope I helped :)
This would probably be based on the number and type of chemical bonds the substance has.
Although I’m not entirely sure what answer you’re looking for, I’d say because most scientific investigations require multiple trials of an experiment