Table of contents

1. Matter and Measurements4h 31m
2. Atoms and the Periodic Table5h 23m
3. Ionic Compounds2h 18m
4. Molecular Compounds2h 18m
5. Classification & Balancing of Chemical Reactions3h 17m
6. Chemical Reactions & Quantities2h 27m
7. Energy, Rate and Equilibrium3h 46m
8. Gases, Liquids and Solids3h 25m
9. Solutions4h 10m
10. Acids and Bases3h 29m
11. Nuclear Chemistry56m
BONUS: Lab Techniques and Procedures1h 38m
BONUS: Mathematical Operations and Functions47m
12. Introduction to Organic Chemistry1h 34m
13. Alkenes, Alkynes, and Aromatic Compounds2h 12m
14. Compounds with Oxygen or Sulfur1h 6m
15. Aldehydes and Ketones1h 1m
16. Carboxylic Acids and Their Derivatives1h 11m
17. Amines39m
18. Amino Acids and Proteins1h 51m
19. Enzymes1h 37m
20. Carbohydrates1h 41m
21. The Generation of Biochemical Energy2h 8m
22. Carbohydrate Metabolism2h 22m
23. Lipids2h 26m
24. Lipid Metabolism1h 45m
25. Protein and Amino Acid Metabolism1h 37m
26. Nucleic Acids and Protein Synthesis2h 54m

10. Acids and Bases

The pH Scale

GOB Chemistry

10. Acids and Bases

The pH Scale

Previous problemNext problem

1:56 minutes

Problem 41

Textbook Question

Complete the following table:

Verified step by step guidance

Step 1: Recall the relationship between pH and the concentration of hydronium ions ([H₃O⁺]). The formula is:

pH = - \log^{(} [H₃O⁺])

. Rearrange this formula to solve for [H₃O⁺]:

[H₃O⁺] = 10^{-} pH

Step 2: Substitute the given pH value (2.50) into the formula to calculate [H₃O⁺]. This will give the concentration of hydronium ions in moles per liter.

Step 3: Use the relationship between [H₃O⁺] and [OH⁻] in water, which is governed by the ion product constant for water:

K w_{=} [H₃O⁺] \times [OH⁻]

. At 25°C,

K w_{=} 10^{- 14}

. Rearrange this formula to solve for [OH⁻]:

[OH⁻] = 10^{- 14} / [H₃O⁺]

Step 4: Determine whether the substance is acidic, neutral, or basic based on the pH value. A pH less than 7 indicates an acidic solution, a pH of 7 indicates a neutral solution, and a pH greater than 7 indicates a basic solution. Since the pH is 2.50, the solution is acidic.

Step 5: Complete the table by filling in the calculated values for [H₃O⁺] and [OH⁻], and indicate that the solution is acidic based on the pH value.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above

Video duration:

Play a video:

Was this helpful?

Key Concepts

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

pH Scale

The pH scale measures the acidity or basicity of a solution, ranging from 0 to 14. A pH of 7 is considered neutral, while values below 7 indicate acidity and values above 7 indicate basicity. The scale is logarithmic, meaning each whole number change represents a tenfold change in acidity or basicity.

Hydronium and Hydroxide Ions

In aqueous solutions, the concentration of hydronium ions (H3O+) and hydroxide ions (OH-) determines the pH. An increase in H3O+ concentration results in a lower pH (more acidic), while an increase in OH- concentration results in a higher pH (more basic). The product of these concentrations is constant at 25°C, known as the ion product of water.

Acidic, Neutral, or Basic Solutions

Solutions can be classified as acidic, neutral, or basic based on their pH values. Acidic solutions have a pH less than 7, neutral solutions have a pH of exactly 7, and basic solutions have a pH greater than 7. The classification helps in understanding the chemical behavior and reactivity of substances in different environments.

Watch next

Master The pH Scale Concept 1 with a bite sized video explanation from Jules

Start learning