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_____ 4. HCO_3 is amphoteric. 5. The complex ion, [Al(H_2 O)6]^3+, in conjugate

ID: 510775 • Letter: #

Question

_____ 4. HCO_3 is amphoteric. 5. The complex ion, [Al(H_2 O)6]^3+, in conjugate acid of [AI(H_2 O)_5 (OH)]^2+ _____ 6. NO_3^- is a weaker base than F. _____7. The pK_a of acetic acid is less than the pK_a of chloroacetic acid. _____8.The addition of NaOAc(s) to HOAc (aq) will lower the pH of the solution. _____9. S^2 is a weaker base tan HS^-. _____10. The ammonium ion is a Br nsted Acid. _____11. The pK_a of acetic acid (K_a = 1.8 times 10^-5) is less than pK_a of nitrous acid (K_a = 4.5 times 10^-4). _____12. Ammonia is a Lewis base. _____13. Silver iodide (aq) (K_sp) = 8.3 times 10^-17) is more soluble than silver chloride (aq) (K_sp = 1.6 times 10^-10). _____14. The % ionization of 0.1 M acetic acid is less than the % ionization of 0.01 M acetic acid.

Explanation / Answer

4. True

HCO3(aq) + OH(aq) -> CO32(aq) + H2O(l)

HCO3(aq) + H3O+(aq)-> H2CO3(aq) + H2O(l)

5. True

[Al(H2O)5(OH)]2+ + H3O+    [Al(H2O)6]3+ + H2O

6. True

HNO3 is a stronger acid than HF

therefore their conjugate base NO3- is weaker than F-

7. False

As chloroacetic acid is more acidic than acetic acid. Therefore its Pka should be less than acetic acid.

8. True

These reactions share a common ion: the OAc- ion. LeChatelier's principle predicts that adding NaOAc to an HOAc should shift the equilibrium between HOAc and the H3O+ and OAc- ions to the left. Thus, adding NaOAc reduces the extent to which HOAc dissociates.

9. False

HS- -> S-2

Since HS- is a weak acid therefore S-2 is a stonger conjugate base. Thus S-2 is a stronger Base than HS-

10. True

A Brønsted-Lowry acid is a proton (hydrogen ion) donor.

11. False

Since Ka of nitrous acid is greater than acetic acid. Thefore PKa of nitrous acid is less than PKa of acetic acid.

12. Ammonia is a lewis base. True

It can donate a lone pair of electron.