Chapter 11.3, Problem 26SSC

(a)

Interpretation Introduction

Interpretation:

In the burning of wood in a campfire, the limiting and excess reactant needs to be identified.

Concept introduction:

A chemical reaction involves the conversion of certain molecules (reactant) to new substance (product) by bond breaking and making. One of the reactants, which is present in limited amount and determines the amount of product is known as limiting reactant. Whereas another reactant is known as excess reactant.

Answer to Problem 26SSC

Limiting reactant = wood

Excess reactant = Oxygen

Explanation of Solution

The burning of wood must occur in the presence of oxygen. Thus here oxygen (atmospheric oxygen) must be excess reactant whereas wood must be limiting reactant as the amount of product formed depends on the amount of wood present. The product of burning of wood are carbon dioxide and water.

(b)

Interpretation Introduction

Interpretation:

In the reaction of airborne sulfur with silver plating on a teapot to produce tarnish (silver sulfide), the limiting and excess reactant needs to be identified.

Concept introduction:

A chemical reaction involves the conversion of certain molecules (reactant) to new substance (product) by bond breaking and making. One of the reactants, which is present in limited amount and determines the amount of product is known as limiting reactant. Whereas another reactant is known as excess reactant.

Answer to Problem 26SSC

Limiting reactant = teapot

Excess reactant = airborne sulfur

Explanation of Solution

In the reaction of airborne sulfur with silver plating on a teapot to produce tarnish (silver sulfide), the airborne sulfur must be excess reactant as it is present in excess in atmosphere whereas teapot has limited metal supply so it must be limiting reactant.

(c)

Interpretation Introduction

Interpretation:

In the reaction of baking powder with batter to form carbon dioxide, the limiting and excess reactant needs to be identified.

Concept introduction:

A chemical reaction involves the conversion of certain molecules (reactant) to new substance (product) by bond breaking and making. One of the reactants, which is present in limited amount and determines the amount of product is known as limiting reactant. Whereas another reactant is known as excess reactant.

Answer to Problem 26SSC

Limiting reactant = baking powder

Excess reactant = batter

Explanation of Solution

In the reaction of baking powder with batter to form carbon dioxidegas. Since baking powder is added in limited amount, so it must be limiting reactant whereas batter must be excess reactant here.