Chapter 19, Problem 1STP

Interpretation Introduction

Interpretation : The type of acid for the given dissociation constant is to be identified.

Concept Introduction : Acids are substances that contain hydrogen and ionize to produce hydrogen ions $\left({\text{H}}^{\text{+}}\right)$ in an aqueous solution.

Answer to Problem 1STP

Correct answer: Option (B)

The acid with dissociation constant value is an aqueous solution that would have a pH lesser than 7.

Explanation of Solution

Reason for correct option:

The acid dissociation constant is the ratio of an acid's dissociated form to its undissociated form. It is denoted as ${\text{K}}_{\text{a}}$ .

It contains both the anion and the hydronium ion.

The given dissociation constant value is small.

The strength of an acid is directly proportional to the value of the dissociation constant.

Since the dissociation constant is small, the acid might not be a strong acid.

It would refer to the weak acid whose pH is nearer to 7.

So, the correct option is B.

Conclusion

Reasons for incorrect options:

Option (A): The value of the acid dissociation constant is small, so it is not be a strong acid.

Option (C): Since the acid dissociation constant is small, it cannot be a strong acid electrolyte.

Option (D): Due to the acid dissociation constant value, the option cannot be all the above.