Answer:
c. HF can participate in hydrogen bonding.
Explanation:
<u>The boiling points of substances often reflect the strength of the </u><u>intermolecular forces</u><u> operating among the molecules.</u>
If it takes more energy to separate molecules of HF than of the rest of the hydrogen halides because HF molecules are held together by stronger intermolecular forces, then the boiling point of HF will be higher than that of all the hydrogen halides.
A particularly strong type of intermolecular attraction is called the hydrogen bond, <em>which is a special type of dipole-dipole interaction between the hydrogen atom in a polar bond</em>, such as N-H, O-H, or F-H, and an electronegative O, N, or F atom.
<u>Answer:</u> The number of moles of gas present is 0.276 moles
<u>Explanation:</u>
To calculate the number of moles of gas, we use the equation given by ideal gas:
PV = nRT
where,
P = Pressure of the gas = 725 mm Hg
V = Volume of the gas = 7.55 L
n = number of moles of gas = ?
R = Gas constant = 
T = Temperature of the gas = 
Putting values in above equation, we get:

Hence, the number of moles of gas present is 0.276 moles
Answer:
Chemical
Explanation:
The change was chemical, because it can no longer be returned to the original form. You cannot get back the bubbles or fizz from the air.