This document provides instructions for homework assignment 3a, which asks students to label acids and bases in chemical reactions and classify given compounds as acids or bases according to Arrhenius, Bronsted-Lowry, and Lewis theories. The document then provides solutions to the questions, labeling reactants in sample reactions as acids or bases and classifying example compounds such as Na2O, SO2, and HF according to the three theories.

1. Homework #3a Due Wednesday, June 27, 2018 Name (4 points) Label the acid and base in each
reaction and determine the reaction direction for each of the following. 1. a. NH3 + H2O .. NH,'
+ OH. b. HCO3(aq) + F(aq)?CO32-(aq) + HF (aq) d. CaO + 2HCN?Ca(CN)2 + H2O 2. (3
points) Define each of the following as either an acid or a base AND determine which definition
(Arrhenius, Bronsted-Lowry, Lewis) applies Compound Na O SO HF CH3NH BF3 (COOH)
Arrhenius Bronsted- Lowry Lewis Acid or Base?
Solution
Arrhenius theory:
An acid is H+ ion donor and a base is a OH- donor when they dissolved in water.
Bronsted theory:
An acid is H+ ion donor and a base is H+ ion accepter in a solution.
Lewis theory:
An acid is accepter of a lone pair of electrons and a base is a donor of a lone pair of
electrons.
a)
NH3 + H2O ----> NH4+ + OH-
Here NH3 accepts a H+ ion or it can donate a lone pair of electrons. so it acts as base. and
H2O is donate a H+ ion so it acts as acid.
b)
HCO3-(aq) + F-(aq) <-----> CO3 2-(aq) + HF(aq)
Here HCO3- donates a H+ ion and F- accepts a H+ ion so HCO3- acts as acid and F- acts as
base. according to Bronsted theory.

2. c)
CH3COOH + H2O <----> H3O+ + CH3COO-
Here CH3COOH donate a H+ ion and H2O Accepts a H+ ion so CH3COOH is acid and
H2O is a base since it accepts a H+ion.
d)
Cao + 2 HCN <-----> Ca(CN)2 + H2O
Here HCN donates H+ ion so it acts as acid and Cao acts as base.
The given compounds are Na2O, SO2, HF, CH3NH2, BF3, (COOH)2
Arrhenius Acids:
HF, (COOH)2
Arrhenius Bases:
-
Bronsted acids:
HF, (COOH)2
Bronsted Bases:
Na2O, SO2, CH3NH2,
Lewis Acids:
HF, BF3, (COOH)2
Lewis bases:
Na2O, So2, CH3NH2,
so finally,
Acids: HF, (COOH)2, BF3,
Bases: Na2O, SO2, CH3NH2