In which of the following processes is it necessary to break covalent bonds as opposed to simply overcoming intermolecular forces?
a. melting mothballs
b. dissolving hydrogen bromide gas in water to form hydrobromic acid
c. vaporizing ethyl alcohol
d. changing ozone to oxygen gas

Mass is the amount of matter in an object.  weight is the measurement of the pull of gravity on an object.  say for example, you travel to the moon which has a different gravitational field compared to the gravitational field of earth. (gravitational fields: earth = 1, moon = 0.165)  now when you are on the moon, the pull of gravity on you is different than on the earth. and as weight is the measurement of the pull of gravity on an object, that means yes, your weight can and will change on the moon.  however, on the moon, on earth or even on jupiter, the amount of mass inside of you remains the same. meaning your physical mass remains constant.  in conclusion it is possible for your weight to change as your mass remains constant. 

The air is going to come out because of the low pressure.