1.883 Grams of copper reacted with excess sulfur to form an unknown Copper sulfide. The reaction creates 2.308 grams of an unknown Copper Sulfide. What I am trying to find Is the empirical formula of the Copper Sulfide. It is either, Copper(I) Sulfide or Copper(II) sulfide. I don't need the answer but rather an explanation of how to solve this problem.

Iknow the answer is a but i don't know why

Butadiene undergoes a reaction at a certain temperature in the gas phase as follows: 2c4h6(g) --> c8h12(g) the following data were collected for this reaction: time (min) [c4h6] (m) 0 0.36 15 0.30 30 0.25 48 0.19 75 0. determine the order of the reaction and the rate constant. 1st order and k = 4.3x10 -4 s-1 1st order and k = 2.3x10-4 s-1 2nd order and k = 4.3x10-4 s-1 2nd order and k = 2.3x10-4 s-1 zero and k = 4.3x10-4 s-1

Which of the following is always a reactant in a combustion reaction? oxygen nitrogen hydrogen carbon