<h2>Hello!</h2>
The answer is: -97.37° C
<h2>Why?</h2>
According to the Charles and Gay-Lussac's Law we have that:

Where:
<em>v</em> is the volume of the gas
<em>t</em> is the temperature of the gas
<em>k </em>is the proportionality constant
From the Gay-Lussac's Law we also have the following relation:

Since we need to find the new temperature (T2) we can use the last equation:

We are asked to find the temperature in Celsius degrees, so, we must convert the result (in K) to Celsius degrees:

So, the temperature is -97.37° C
Have a nice day!
Answer C
I could be wrong
Explanation
Here is a picture of which shows you how many valence electrons are in the Lewis structure of xeo4
We are told we have an oxyacid of the formula HOFO. We will assume the atoms are in this order and will draw a proper lewis structure for this compound by first drawing bonds between each of the 4 atoms and then place the remaining electron pairs on each atom:
.. .. ..
H - O - F - O:
·· ·· ··
We can calculate the formal charge of an atom using the following formula:
Formal charge = [# of valence electrons] - [# of non-bonded electrons + # of bonds]
H: Formal charge = [1]-[0+1] = 0
O: Formal charge = [6]-[4+2] = 0
F: Formal charge = [7]-[4+2] = +1
O: Formal charge = [6]-[6+1] = -1
As we can see the overall charge of the molecule is neutral since the fluorine as a +1 charge and the oxygen a -1 charge.