Chapter 3.5, Problem 3.12CE

(a)

Interpretation Introduction

Interpretation:

For the given ${\text{NaOH (aq) + HNO}}_{\text{3}}\text{(aq) }\to {\text{ NaNO}}_{\text{3}}{\text{(aq) + H}}_{\text{2}}\text{O (l)}$ reaction, the oxidation and reduction reaction has to be identified. Oxidizing & reducing agent also has to be identified.

Concept introduction:

Redox reaction: Redox reaction is a type of chemical reaction, where both the oxidation and reduction occur at the same time. In a redox reaction, one of the reactant is oxidized and the other is reduced simultaneously.

Oxidation number:

The oxidation number of an element is zero. The oxidation number of a monoatomic ion equals its charge.

The oxidation number is zero for the summation of the oxidation numbers complete atoms in a complete formula.

The charge on the ion is equal to the summation of the oxidation numbers of complete atoms in poly atomic ion.

The oxidation state of alkali metal $(\text{Li, Na, K, Rb, Cs})$ is $+1$, and alkaline earth metal is $\text{(Be, Mg, Ca, Sr, Ba)}$ is $+2$.

The oxidation state of hydrogen is $+1$ (without bonding with metals), the oxidation state of oxygen is $-2$.

An oxidizing agent gains the electrons and is reduced in a chemical reaction.  It is an electron acceptor.

A reducing agent loses electrons and is oxidized in a chemical reaction.  It is an electron donor.

The oxidation state is called as oxidation number, which describes degree of oxidation (loss of electrons) of an atom in a chemical compound. Theoretically, the oxidation state is positive, negative or zero.

(b)

Interpretation Introduction

Interpretation:

For the given ${\text{4 Cr(s) + 3 O}}_{\text{2}}\text{(g) }\to {\text{ 2 Cr}}_{\text{2}}{\text{O}}_{\text{3}}\text{(s)}$ reaction, the oxidation and reduction reaction has to be identified. Oxidizing & reducing agent also has to be identified.

Concept introduction:

Refer to part (a)

(c)

Interpretation Introduction

Interpretation:

For the given ${\text{NiCO}}_{\text{3}}\text{(s) + 2 HCl(aq) }\to {\text{ NiCl}}_{\text{2}}{\text{(aq) + H}}_{\text{2}}{\text{O(l) + CO}}_{\text{2}}\text{(g)}$ reaction, the oxidation and reduction reaction has to be identified.

Concept introduction:

Refer to part (a)

(d)

Interpretation Introduction

Interpretation:

For the given ${\text{Cu(s) + Cl}}_{\text{2}}\text{(g) }\to {\text{ CuCl}}_{\text{2}}\text{(s)}$ reaction, the oxidation and reduction reaction has to be identified.

Concept introduction:

Refer to part (a)