D. The empirical formula and the molar mass
Na2S2O3(aq) + 4Cl2( g) + 5H2O = 2NaHSO4(aq) + 8HCl(aq)
1)How many moles of HCl can form from 0.21 mol of Cl2?
0.21 mol Cl2 ( 8 mol HCl / 4 mol Cl2 ) = 0.42 mol HCl
2)How many moles of H2O are required for the reaction of 0.18 mol of Cl2?
0.18 mol Cl2 ( 5 mol H2O / 4 mol Cl2 ) = 0.225 mol H2O
3)How many moles of H2O react if 0.50 mol HCl is formed?
0.50 mol HCl ( 5 mol H2O / 8 mol HCl ) = 0.3125 mol H2O
Answer:
Electrons on atoms have different amounts of energy proportional to the distance of their orbital from the nucleus. So in the flame, electrons get excited and pushed to higher energy levels by the heat energy. When they fall back down, they give off photons of light of different colors, based upon how far they fall.
