Question

calculate mass in grams in bromine produced from the decomposition reaction of 0.56kg of chromium (III) bromide. please help

Answer 1

chromium(III) bromide is actually CrBr3, where chromium has a valence of 3+ and bromine a valence of 1- to match a neutrally charged molecule. Find the molecular weight of CrBr3 and divide it by the mass of the original reactant available (0.56Kg) remember, everything MUST be in the same scale (gr or Kg). Then you will obtain the moles of reactant provided. Now if you have three molecules of bromide per one molecule of chromium, multiply the molar mass of bromine BY three and BY the total moles obtained in the initial step to get the mass of all the three atoms of bromine per molecule of reactant.