How do I choose between Ka1 and Ka2?

The Ka1 value on its own is large, and the Ka2 value is 10^-2 which by itself is also significant in the equilibrium. As such, unlike most other acids with multiple Hydrogens, sulfuric acid has a high Ka2 which makes it strong.

How do you calculate Ka2?

Ka2 = = = 6.3 x 10-8 = y (assume y << 0.19) y = 6.3 x 10-8 (very small – assumption definitely okay !!) (2) [H+] from second dissociation is negligible!

Is Ka1 always larger than Ka2?

My chemistry textbook says that in the ionisation of a polyprotic acid with Ka1, Ka2 and so on, ‘the first Ka is usually the largest.

Why is Ka1 Ka2?

This is because the negatively charged HSO4- ion has much less tendency to donate a proton to H2O as compared to neutral H2SO4.

How do you solve for KB?

Solve the equation for Kb by dividing the Kw by the Ka. You then obtain the equation Kb = Kw / Ka. Put the values from the problem into the equation. For example, for the chloride ion, Kb = 1.0 x 10^-14 / 1.0 x 10^6.

Why is Ka2 Ka1?

Why is Ka Ka for H2SO4 in water?

This is because a neutral H2SO4 has a much higher tendency to lose a proton than the negatively charged HSO4- . Thus, the former is a much stronger acid than the latter.

Why is K K for H₂so in water?

How is the KA1 of an acid calculated?

Ka1 can be calculated using the initial concentration of the acid and the initial pH of the solution. If Ka1 is significantly greater than the other ionization constants by a factor of at least 103, the [H3O+1] can be assumed to come essentially from only the first ionization and can be calculated from the initial pH.

How is the pH of ka2 calculated in titration?

If Ka1 and Ka2 are significantly different, the pH at the first equivalence point will be approximately equal to the average of pKa1 and pKa2. Ka2 can be calculated from the pH at the second half-equivalence point. At this point in the titration, half of the moles of H2PO4-1 have been converted to HPO4-2.

How to solve the equation for k a?

When given the pH value of a solution, solving for K a requires the following steps: Set up an ICE table for the chemical reaction. Use the concentration of H 3 O + to solve for the concentrations of the other products and reactants. Plug all concentrations into the equation for K a and solve.

Is the Ka3 for H3PO4 too close to kW?

The Ka3 for H3PO4 is too close to Kw so a third jump in pH is usually not seen at the third equivalence point. Ka3 can be calculated from the pH at the third half-equivalence point. At this point in the titration, half of the moles of HPO4-2 have been converted to [PO4-3].