Textbook Question
Calculate the concentration of all species in a 0.155 M solution of H2CO3.
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Ch.16 - Acids and Bases
Chapter 16, Problem 116b
Consider a 0.10 M solution of a weak polyprotic acid (H2A) with the possible values of Ka1 and Ka2 given here: b. Ka1 = 1.0 * 10^-4; Ka2 = 1.0 * 10^-5. Calculate the contributions to [H3O+] from each ionization step. At what point can the contribution of the second step be neglected? c. Ka1 = 1.0 * 10^-4; Ka2 = 1.0 * 10^-6.
Verified step by step guidance1
<insert step 1> Identify the ionization steps for the polyprotic acid H2A. The first ionization step is H2A ⇌ H+ + HA-, and the second ionization step is HA- ⇌ H+ + A2-.
<insert step 2> For the first ionization step, use the expression for the acid dissociation constant: Ka1 = [H+][HA-]/[H2A]. Assume initial concentrations and solve for [H+].
<insert step 3> For the second ionization step, use the expression for the acid dissociation constant: Ka2 = [H+][A2-]/[HA-]. Use the [H+] from the first step to solve for the additional [H+] contributed by the second ionization.
<insert step 4> Compare the [H+] contributions from the first and second ionization steps. Determine when the contribution from the second step is negligible by comparing the magnitude of Ka1 and Ka2.
<insert step 5> For part c, repeat the process with the new value of Ka2 = 1.0 * 10^-6, and analyze the contributions to [H3O+] from each ionization step.>
Related Practice
Textbook Question
Calculate the [H3O+] and pH of each H2SO4 solution. At approximately what concentration does the x is small approximation break down?
a. 0.50 M b. 0.10 M c. 0.050 M
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Textbook Question
Consider a 0.10 M solution of a weak polyprotic acid (H2A) with the possible values of Ka1 and Ka2 given here.
a. Ka1 = 1.0 × 10–4; Ka2 = 5.0 × 10–5
Calculate the contributions to [H3O+] from each ionization step. At what point can the contribution of the second step be neglected?
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Open Question
Based on their molecular structure, choose the stronger acid from each pair of binary acids, and explain your choice: a. HF and HCl b. H2O and HF c. H2Se and H2S.
Textbook Question
Based on molecular structure, arrange the binary compounds in order of increasing acid strength. Explain your choice. H2Te, HI, H2S, NaH
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Open Question
Based on their molecular structure, pick the stronger acid from each pair of oxyacids. Explain your choice for the following pairs: a. H2SO4 or H2SO3 b. HClO2 or HClO c. HClO or HBrO d. CCl3COOH or CH3COOH.