How many moles in 4.2 grams of NaCl

If a gas has an initial pressure of 101kpa and a volume of 10l, then it expands to a volume of 20l, what is the new pressure?

1) a. water molecule breaks up into hydrogen and oxygen on passing electricity. does this involve breaking intermolecular or intramolecular forces of attraction. explain b. on boiling water changes to water vapor. does this involve breaking intermolecular or intramolecular forces of attraction. explain methanol evaporates faster than water. contrast the intermolecular forces and the vapor pressures of methanol and water?

How is the electron sea model of metallic bonding different from the band theory? how are they the same? give at least one similarity and one difference between the models