Skip to main content
Ch.16 - Acids and Bases
Chapter 16, Problem 127c

Based on these molecular views, determine whether each pictured acid is weak or strong.
Molecular view of formic acid in water, showing HCOOH, HCOO-, and H3O+ ions.

Verified step by step guidance
1
Identify the species present in the solution: HCOOH (formic acid), HCOO- (formate ion), and H3O+ (hydronium ion).
Understand that a strong acid completely dissociates in water, while a weak acid only partially dissociates.
Observe the molecular view: there are both HCOOH molecules and HCOO- ions present, indicating that not all HCOOH has dissociated.
Note the presence of H3O+ ions, which are produced when an acid donates a proton to water.
Conclude that since both the undissociated form (HCOOH) and the dissociated form (HCOO-) are present, formic acid is a weak acid.

Verified Solution

Video duration:
1m
This video solution was recommended by our tutors as helpful for the problem above.
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Acid Strength

Acid strength refers to the ability of an acid to donate protons (H+) in a solution. Strong acids completely dissociate in water, releasing all their protons, while weak acids only partially dissociate. This distinction is crucial for understanding the behavior of acids in chemical reactions and their impact on pH levels.
Recommended video:
Guided course
03:51
Binary Acid Strengths

Dissociation Equilibrium

Dissociation equilibrium describes the balance between the undissociated acid and its ions in solution. For weak acids, this equilibrium lies to the left, meaning that only a fraction of the acid molecules dissociate into ions. The presence of both the undissociated acid and its ions, as shown in the image, indicates that formic acid is a weak acid.
Recommended video:
Guided course
02:35
Thermal Equilibrium

Conjugate Base

The conjugate base of an acid is the species that remains after the acid donates a proton. In the case of formic acid (HCOOH), its conjugate base is the formate ion (HCOO-). Understanding the relationship between an acid and its conjugate base is essential for predicting the behavior of acids in solution and their relative strengths.
Recommended video:
Guided course
00:50
Strength of Conjugate Acids and Bases
Related Practice
Textbook Question

Identify the Lewis acid and Lewis base from among the reactants in each equation. a. Fe3+(aq) + 6 H2O(l) ⇌ Fe(H2O)63+(aq) b. Zn2+(aq) + 4 NH3(aq) ⇌ Zn(NH3)42+(aq) c. (CH3)3N(g) + BF3(g) ⇌ (CH3)3NBF3(s)

1253
views
Textbook Question

Identify the Lewis acid and Lewis base from among the reactants in each equation. a. Ag+(aq) + 2 NH3(aq) ⇌ Ag(NH3)2+(aq)

1113
views
Textbook Question

Identify the Lewis acid and Lewis base from among the reactants in each equation. b. AlBr3 + NH3 ⇌ H3NAlBr3 c. F(aq) + BF3(aq) ⇌ BF4(aq)

442
views
Textbook Question

Based on these molecular views, determine whether each pictured acid is weak or strong.

Textbook Question

The binding of oxygen by hemoglobin in the blood involves the equilibrium reaction: HbH+(aq) + O2(aq) ⇌ HbO2(aq) + H+(aq) In this equation, Hb is hemoglobin. The pH of normal human blood is highly controlled within a range of 7.35 to 7.45. Given the above equilibrium, why is this important? What would happen to the oxygen-carrying capacity of hemoglobin if blood became too acidic (a dangerous condition known as acidosis)?

10065
views
Textbook Question

Carbon dioxide dissolves in water according to the equations:

CO2(g) + H2O(l) ⇌ H2CO3(aq)

H2CO3(aq) + H2O(l) ⇌ HCO3(aq) + H3O+(aq)

Carbon dioxide levels in the atmosphere have increased about 20% over the last century. Given that Earth's oceans are exposed to atmospheric carbon dioxide, what effect might the increased CO2 be having on the pH of the world's oceans? What effect might this change be having on the limestone structures (primarily CaCO3) of coral reefs and marine shells?

8650
views