Chapter U4.84, Problem 5E

(a)

Interpretation Introduction

Interpretation: The lemon, which tastes sour, needs to be classified as an acid or a base.

Concept Introduction:

On the basis of taste, reactivity and presence of ions; substances can be classified as acidic and basic. An acidic substance can be defined as the substance that can give ${\text{H}}^{\text{+}}$ ions in the solution. A basic substance can give ${\text{OH}}^{\text{-}}$ ions in its solution.

Answer to Problem 5E

Since lemon juice is sour in taste so it is acidic in nature.

Explanation of Solution

Acidic and basic substance can also be classified on the basis of taste. Acidic substance are sour in taste whereas basic substances are bitter in taste.

Since lemon juice is sour in taste so it is acidic in nature.

(b)

Interpretation Introduction

Interpretation: The solution of washing soda that turns cabbage juice green at 25°C needs to be classified as acidic or basic.

Concept Introduction:

Based on taste, reactivity and presence of ions; substances can be classified as acidic and basic. An acidic substance can be defined as the substance that can give ${\text{H}}^{\text{+}}$ ions in the solution. A basic substance can give ${\text{OH}}^{\text{-}}$ ions in its solution.

Answer to Problem 5E

Since solution of washing turns cabbage juice green, so it is basic in nature.

Explanation of Solution

Cabbage juice is an acid-base indicator; it turns from red to green in the presence of basic substances. Thus, the solution of washing soda that turns cabbage juice green at 25°C is basic in nature.

(c)

Interpretation Introduction

Interpretation: The dilute solution of potassium hydroxide that feels slippery at 25°C needs to be classifiedas acidic or basic.

Concept Introduction:

On the basis of taste, reactivity and presence of ions; substances can be classified as acidic and basic. An acidic substance can be defined as the substance that can give ${\text{H}}^{\text{+}}$ ions in the solution. A basic substance can give ${\text{OH}}^{\text{-}}$ ions in its solution.

Answer to Problem 5E

Since dilute solution of potassium hydroxide feels slippery, it is basic in nature.

Explanation of Solution

Acidic and basic substance can also classified on the basis of their physical properties like taste, slippery feel etc. Since dilute solution of potassium hydroxide solution has a slippery feel so it proves that it is a basic solution because basic solutions feels slippery on touch.

(d)

Interpretation Introduction

Interpretation: The solution of sugar with pH 7 at 25°C needs to classify as acidic or basic solution.

Concept Introduction:

On the basis of taste, reactivity and presence of ions; substances can be classified as acidic and basic. An acidic substance can be defined as the substance that can give ${\text{H}}^{\text{+}}$ ions in the solution. A basic substance can give ${\text{OH}}^{\text{-}}$ ions in its solution.

Answer to Problem 5E

Since sugar solution has pH 7 therefore it should be neutral.

Explanation of Solution

Acidic and basic substance can also classified on the basis of their physical properties like taste, slippery feel etc. Since sugar solution has pH 7 therefore it should be neutral. The pH value ranges from 0 to 14, with neutral point 7.

(e)

Interpretation Introduction

Interpretation: The drain cleaner solution with pH 12 at 25°C needs to classify as acidic or basic solution.

Concept Introduction:

On the basis of taste, reactivity and presence of ions; substances can be classified as acidic and basic. An acidic substance can be defined as the substance that can give ${\text{H}}^{\text{+}}$ ions in the solution. A basic substance can give ${\text{OH}}^{\text{-}}$ ions in its solution.

Answer to Problem 5E

Since drain cleaner solution has pH 12 therefore it should be basic in nature.

Explanation of Solution

Acidic and basic substance can also classified on the basis of their physical properties like taste, slippery feel etc. Since drain cleaner solution has pH 12 therefore it should be basic. The pH value ranges from 0 to 14, with neutral point 7. The range of acidic solution is 0-7 and that of basic solution is 7 to 14 thus, the pH value 12 represents the basic nature.