posted by Tara on .
I have spent the last 6 hours trying to figure this out and have talked to my teacher and apparently i canoot get it right as i have to explain sulfate ions other things i don't understand (never took chem before)
questions i need help with
Na2so4 .05mol/l are reacted with cacl2 (.0125,0.05, 0.075, 0.10 mol/l)
in trails 2-4 parcipitate does not change.
Describe would would ocur when the products of these trails are tested.
Explain why the mass of percipate did not differ in the last three trails.
How would this support the concept of an equilibrium system having a forward and reverse reaction.
please help i have come up with answers but they are not what my teacher is looking for.
i should also explain that i know the limiting and excess agents and how after a limited reaction is complete no further reaction can occur leaving an excess regent, and well as dynamix equilbruims however my teacher wants more
just gonna post my answer to see if more can be added or fixed
1. In trail one CaCl2 will react completely (limiting regent) which limits the complete reaction of NaSO4 (excess regent) therefore creating a precipitate of sulfur. In trails 2-4 as the concentrations increase the mass of the precipitate will not change because the limiting regent Naso4 will have reacted completely and the excess of CaCl2 will no longer be able to produce more CaSO4 as NaSO4 limiting to its production.
2.The mass of precipitate does not change due to the limiting regent being fully reacted so that no further reaction occurs it remains the same because the excess CaSO4 causes the chemical reaction to reverse at some point to return or maintain its equilibrium.
3. not sure how to answer supposed to refer to number of ions and striconometry