Acrystalline material containing 30 grams of barium chloride crystals was placed into an oven at 400 degrees c and heated for two hours. it was then cooled and weighed. the new mass was less than before it was heated, containing 20 grams if barium chloride. how is this possible?

it is possible maybe the crystalline material containing 30 g of barium chloride is a hydrated barium chloride. So when it was heated, the water bounded was evaporated and the remaining barium chloride is only 20 g. I hope this can help.

given:

mass of na = 115 g

excess cl2

to determine:

mass of nacl produced

explanation:

given reaction is-

2na(s) + cl2(g) → 2nacl(s)

since cl2 is in excess, na will be the limiting reagent

as per the reaction stoichiometry na: nacl = 1: 1

i.e. moles of na reacted = moles of nacl formed

now, # moles of na = mass of na/atomic mass

                                  = 115 g/23 g.mol-1 = 5 moles

therefore, moles of nacl = 5

molar mass of nacl = 58 g/mol

mass of nacl = 5 moles * 58 g.mol-1 = 290 g

ans: amount of nacl produced = 290 g