Given 3600 g of uranium 235 . it has a half life of 40,000 years . how much is left after 240,000 years ?

The answer to your question is: 56.25 g of Uranium

Explanation:

Data

mass  = 3600 g of Uranium 235

half life = 40000 years

How much after 240 000 years

                         3600 g of Uranium                   right now

                          1800 g                                      40 000 years

                            900 g                                     80 000 years

                            450 g                                    120 000 years

                            225 g                                    160 000 years

                            112.5 g                                   200 000 years

                            56.25 g                                 240 000 years

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

what does the table look like