# Chemistry

posted by .

1.0L of aqueous solution in which [H2CO3]=[HCO3^-]=0.10M and has [H^+]=4.2E-7. What is the concentration of [H^+] ofter 0.005 mole of NaOH has been added?

H2CO3 ==> H^+ + HCO3^-

k1 = (H^+)(HCO3^-)/(H2CO3)
I don't know if you are supposed to calculate or to look up k1. However, you can calculate it as follows.
Since (HCO3^-) = (H2CO3) [both are 0.1 M), then plugging in 0.l M for each gives k1 = (H^+).
If we start with 0.1 mol H2CO3 and add 0.005 mol NaOH, we have 0.1 - 0.005 mols H2CO3 remaining and an extra 0.005 mol HCO3^- formed to make the final (HCO3^-)= 0.1 + 0.005 = ??
Plug k1, H2CO3, and HCO3^- into the k1 expression above and solve for (H^+). I found 3.97 x 10^-7. Post your work if you have trouble. By the way, it is a longwe way but you can also use the Henderson-Hasselbalch equation. Note also that this is a buffer solution and the H^+ didn't change much even though an amount of NaOH equivalent to 5% was added. That's what it is supposed to do. 0.005 mol NaOH added to an unbuffered solution would change the H^+ to 2 x 10^-12.

## Similar Questions

1. ### chemistry

It's hydrogen carbonate, which is HCO3- Should the reactant be H2CO3?
2. ### Chemistry-Repost

Write formula equations and net ionic equations for the hydrolysis of sodium carbonate in water. Responses Chemistry - DrBob222, Friday, April 24, 2009 at 10:50pm The hydrolysis of Na2CO3 ends us as the hydrolysis of the carbonate …
3. ### Chemistry

4) Which of the following is the most effective buffer system for a pH value of 4.45?
4. ### chemistry

In titration of a 0.10M soln of Na2Co3 with HCL which of the following will be present in the largest concentration at the first equivalence point?
5. ### chemistry

If 0.1200g of sodium carbonate is dissolved in 50 mL of water and titrated with 0.1000 M HCl, how many mL of HCl will be required to reach the second endpoint?
6. ### Chemistry

Calculate [CO32- ] in a 0.019 M solution of CO2 in water (H2CO3). If all the CO32- in this solution comes from the reaction shown below, what percentage of the H+ ions in the solution is a result of the dissociation of HCO3‾?
7. ### chemistry

For 6.0*10^-2 M H2CO3, a weak diprotic acid, calculate the following values. Use ionization constants of H2CO3: Ka1=4.4*10^-7, Ka2=4.7*10^-11, as necessary. PART A: [H3O^+] M PART B: [HCO3^-] M PART C: [CO3^2-] M
8. ### Chemistry

Complete the charge balance equation for an aqueous solution of H2CO3 that ionizes to HCO3^- and CO3^2- ______ = ______ + _______ + _______ Given choices: [HCO3^-],[CO3^2-], [OH^-], 2[H^+], [H2CO3], 2[CO3^2-], 3[H^+], {H^+] I don't …
9. ### Chemistry

Complete the following equilibrium reactions that are pertinent to an aqueous solution of Ag2CO3. Physical states, s, l, g, and aq, are optional. So far I worked it out to be: Ag2CO3(s) <--> 2Ag^+ + CO3^(2-) H2CO3(aq) + H2O(l) …
10. ### chemistry

When a base is introduced into this buffer, which of H2CO3 and HCO3− reacts with the base to maintain the pH of the solution?

More Similar Questions