How do you calculate delta[S2O8 2-] in iodine clock reaction?
Here is a site that explains the iodine clock reaction and all of its various forms.
http://en.wikipedia.org/wiki/Iodine_clock_reaction
The one you want to read about (read them all--all are interesting and contain interesting chemistry) is the persulfate one. The change in persulfate can be calculated knowing about you started with. It is just moles initially -0 = moles used. The clock runs cosn when all of the persulfate is used.
To calculate the change in concentration of S2O8 2- in an iodine clock reaction, we need to know the balanced equation for the reaction and the initial and final concentrations of the other reactants.
Let's assume the balanced equation for the reaction is:
S2O8 2- + 2I- → I2 + 2SO4 2-
To calculate delta[S2O8 2-], we will use the method of initial rates. This involves measuring the initial and final concentrations of other reactants and using their stoichiometric coefficients in the balanced equation.
1. Firstly, measure the initial and final concentrations of I- (the other reactant) in the reaction. Let's call these values [I-]initial and [I-]final.
2. Write down the stoichiometric ratio between S2O8 2- and I- from the balanced equation. In this case, it is 1:2. This means 1 mole of S2O8 2- reacts with 2 moles of I-.
3. Calculate the change in concentration of I- using the equation:
Δ[I-] = [I-]final - [I-]initial
4. Since the stoichiometric ratio between I- and S2O8 2- is 2:1, the change in concentration of S2O8 2- can be calculated using the equation:
Δ[S2O8 2-] = (1/2) * Δ[I-]
So, to calculate delta[S2O8 2-], you need to know the initial and final concentrations of I-, and then apply the stoichiometric ratio to determine the change in concentration of S2O8 2-.
To calculate the change in concentration of S2O8 2- (delta[S2O8 2-]) in the iodine clock reaction, you need to know the rate of consumption of S2O8 2- as the reaction progresses. Given that the reaction is an iodine clock reaction, you can determine the change in concentration of S2O8 2- by monitoring the color change of the reaction mixture.
Here are the steps to calculate delta[S2O8 2-] in the iodine clock reaction:
1. Set up the iodine clock reaction experiment, which typically involves mixing solutions containing S2O8 2-, iodide ions (I-), and a catalyst (such as starch or thiosulfate).
2. Observe the reaction mixture closely for a color change. The reaction typically starts as colorless and gradually turns blue or dark when a certain amount of iodine is produced.
3. Record the time it takes for the color change to occur. This is the reaction time or "clock time."
4. Repeat the experiment multiple times to obtain an average reaction time.
5. Start with a known initial concentration of S2O8 2- (usually provided in the experiment). This concentration is typically given in moles per liter (mol/L) or molarity (M).
6. Use the average reaction time obtained in step 4 to calculate the rate of S2O8 2- consumption. The rate is defined as the change in concentration of S2O8 2- per unit time (usually in seconds). Divide the initial concentration by the reaction time to obtain the rate.
Rate = [S2O8 2-] initial / Reaction time
7. Finally, to calculate delta[S2O8 2-], multiply the rate obtained in step 6 by the time interval or "delta t" for which you want to calculate the change in concentration.
Delta[S2O8 2-] = Rate * Delta t
By following these steps, you can determine the change in concentration of S2O8 2- in the iodine clock reaction.