Acids and BASE problem!! PLEASE HELP!!!! PLEASE!!

Question

Write reactions showing the behavior of hydrochloric acid (HCl) as (a) an Arrhenius acid, and (b) a Brønsted-Lowry acid.

Write a balanced equation showing the behavior of ammonia, NH3, as a Brønsted-Lowry base. Using a chemical equation, explain why ammonia cannot behave as an Arrhenius base.

Write a chemical equation showing the reaction between ammonia and boron trifluoride, BF3, in a Lewis acid-base reaction. Show how the covalent bond forms.

Write chemical formulas representing each of the six types of compounds listed below. Use examples other than those listed in questions 4-7. For each compound, justify your answer.

Arrhenius acid

Arrhenius base

Brønsted-Lowry acid

Brønsted-Lowry base

Lewis acid

Lewis base

Answer 1

1. HCl gives H^+ + Cl^-  Proton donors are acids - Arrhenius

HCl + H2O gives H3O^+ + Cl^- Proton donor is an acid and a proton acceptor is a base  In the above equation the reverse one in which Cl^- is a base and H3O^+ is an acid and in forward case HCl is an acid and H2O is a base.

2.  NH3 + H2O gives NH4^+  +  OH^- NH3 is a proton acceptor.

NH3 cannot be a Arrhenius base since it has no hydroxyl group.

3. NH3 + BF3 gives NH3-BF3.  NH3 carries an unshred pair of electron on nitrogen atom as it donates the one to BF3 ( having sextet ) a covalent coordinate bond is formed an arrow from N to B should be made.

4. Arrhenius acid: H2SO4 gives H^+ + HSO4^-

Arrhenius base: NaOH, NH4OH, Ca(OH)2 etc  NaOH gives Na^+ + OH^-

Bronsted Acid CH3COOH + H2O gives CH3COO^-  +  H3O^+

Bronsted Base: NH4+ + H2O gives NH3  +  H3O^+

Lewis acid: FeCl3, AlCl3, BCl3 all are having sextet (having six electron around the metal), NH4^+

Lewis base: NH3, H2O, Cl^-, CN^- etc having one or two unshared pair of electron or a negative charge over the species.

Answer 2

I think you need to review the three separate definitions of acid-base, which are Arrhenius, Lowry-Bronsted, and Lewis.

A lot of students have trouble with this. Discuss it with your classmates.

Answer 3

(a) HCl ==> H+ + Cl-

(b) HCl + H2O  ==>  H3O+ + Cl-

.....HCl is an acid because it donates a proton (H+) to H2O.

(c) NH3 + H2O  <==>  NH4+ + OH-

....NH3 is a base because it accepts a proton from H2O.

(d) NH3 <==> can't "split up" to give OH-

(e) BF3 + NH3 <==>  NH3BF3

....The N donates its unbonded pair to the B (which only has 6 e's in its outer shell) to form a covalent bond. Thus NH3 (an e- pair donor) is a Lewis base, and BF3 (an e- pair acceptor) is a Lewis acid.

1. HNO3

....HNO3  ==>  H+ + NO3-

2. NaOH

....NaOH ==>  Na+ + OH-

3. HF

....HF + H2O  <==>  H3O+ + F-

4. CN- (cyanide)

....CN- + H2O  <==>  HCN + OH-

5. Al3+

....Al3+ + 6H2O  <==>  Al(H2O)6 3+

6. O 2- (oxide)

....O 2- + SO3  <==>  SO4 2-