sketch a ph curve for the titration 40.00 mLof 0.100M hyrazine H2NNH2(aq) having a Kb of 3.0 x 10^-6 by 0.100 M HCIO4(aq)
Calculate [H3O+] and [OH-] in 0.18M hyrdobromic acid, HOBr(aq) having, Ka of 2.0 x 10^-9
Hydrobromic acid is HBr. HOBr is hypobromous acid.
To sketch a pH curve for this titration, we need to know the reaction that occurs between hydrazine (H2NNH2) and perchloric acid (HCIO4) and understand the concept of pH.
The reaction between hydrazine and perchloric acid can be represented as follows:
H2NNH2(aq) + HCIO4(aq) -> H2NNH3+(aq) + CIO4-(aq)
The key to understanding the pH curve is to identify the equivalence point and the initial and final pH values.
Here are the steps to calculate the pH at different points during the titration:
Step 1: Calculate the moles of hydrazine and perchloric acid:
Moles of hydrazine = volume (in L) × concentration (in M)
Moles of perchloric acid = volume (in L) × concentration (in M)
Step 2: Determine the limiting reagent and calculate the moles of the products produced:
Since hydrazine and perchloric acid react in a 1:1 ratio, the limiting reagent will be the one that is completely consumed. The reactant with the lower number of moles will be the limiting reagent.
Let's say hydrazine is the limiting reagent. Then, the moles of H2NNH3+ and CIO4- produced will be the same as the moles of H2NNH2.
Step 3: Calculate the total volume of the solution after each addition of perchloric acid:
The total volume of the solution will be the sum of the initial volume of hydrazine and the volume of perchloric acid added.
Step 4: Calculate the concentration of the products H2NNH3+ and CIO4-:
The concentration of these products can be determined by dividing the moles of each product by the total volume of the solution.
Step 5: Calculate the pOH and pH:
pOH can be calculated using pOH = -log[OH-]. Since we have the concentration of H2NNH3+, we can calculate the concentration of OH- (which is equal to the concentration of the conjugate base, CIO4-) and convert it into pOH.
pH can be calculated using pH + pOH = 14. Therefore, pH = 14 - pOH.
Repeat this calculation for each point where you want to determine the pH.
Step 6: Plot the pH curve:
Using the pH values calculated in step 5, plot a graph with the volume of the perchloric acid added on the x-axis and the pH on the y-axis. Connect the points to obtain the pH curve.
It's important to note that the shape of the pH curve will depend on the pKa and pKb values of the acid and base involved in the titration.
By following these steps, you should be able to sketch a pH curve for the provided titration.