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

To answer these questions, let's break them down one by one:

1. What would occur when the products of these trials are tested?

To understand this, we need to know the reaction that occurs when sodium sulfate (Na2SO4) reacts with calcium chloride (CaCl2). The balanced equation for this reaction is:

Na2SO4 + CaCl2 -> CaSO4 + 2NaCl

This reaction produces calcium sulfate (CaSO4) and sodium chloride (NaCl). When these products are tested, we would expect to observe the formation of a white precipitate of calcium sulfate and a clear solution of sodium chloride.

2. Explain why the mass of precipitate did not differ in the last three trials.

In the last three trials, the concentration of CaCl2 used was varied (0.05, 0.075, 0.10 mol/L). However, the mass of precipitate remains the same in each trial. This can be attributed to the concept of limiting reagents.

In the reaction between Na2SO4 and CaCl2, the reactants are in a 1:1 mole ratio. This means that for every 1 mole of Na2SO4, 1 mole of CaCl2 reacts. In the first trial, the concentration of CaCl2 is 0.0125 mol/L, which is lower than the other three trials. As a result, there is excess Na2SO4 compared to the CaCl2.

In the last three trials, the concentration of CaCl2 is higher, but the concentration of Na2SO4 remains constant. This means that there is sufficient CaCl2 to react with all the Na2SO4 in each trial. Therefore, the mass of the precipitate remains the same because the reaction has reached its limiting reagent, which is CaCl2.

3. How would this support the concept of an equilibrium system having a forward and reverse reaction?

In this scenario, the reaction between Na2SO4 and CaCl2 is a precipitation reaction. At the beginning of the reaction, the reactants are in different concentrations, and the reaction proceeds in the forward direction to form the precipitate.

However, as the reaction progresses, the concentration of the products (CaSO4 and NaCl) increases, while the concentration of the reactants (Na2SO4 and CaCl2) decreases. This change in concentration affects the rate of the forward reaction.

Eventually, the forward reaction reaches a point where the rate of the forward reaction becomes equal to the rate of the reverse reaction, forming a dynamic equilibrium. In this equilibrium state, the concentrations of reactants and products remain constant.

In the last three trials, the constant mass of precipitate indicates that the reaction system has reached equilibrium. This supports the concept of an equilibrium system having a dynamic balance between the forward and reverse reactions, where the rates of both reactions become equal.

I hope this explanation helps you understand the questions better. If you have any further queries, please feel free to ask.