Identify whether the impurity in your unknown was sodium acetate or napon unknown was sodium acetate or narasthalene. exp how you know by using evidence from the chosen recrystallization solvent, disa intermolecular forces involved, and from the mixture melting point

The mass has escaped into a gas which you can not see so the law stays true.

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. 

Fine out you self hx