Chapters_4___5_Chemical_Reactions_Libre_out_of_order

Chapters Overview

• Chapters Covered: 4 + 5 on Solutions and Chemical Reactions

• Reminder: Sections 4.1 – 4.3 were discussed in Chapter 3 in General Chemistry I.

Real-Life Chemistry

• Everyday Chemistry: Chemistry is present all around us, especially in culinary applications, such as baking.

• Baking Insight: Many chemical reactions/processes occur during cookie baking, from mixing the ingredients to enjoying the final product.

Solution Concentration and Dilution (Sections 4.1-4.3)

Objectives

• Define and describe: solution properties, concentration units, and perform calculations.

• Calculate solution concentrations, including Molarity, mass percentage, and parts-per-million.

Solutions

• Definition: Homogeneous mixtures consisting of a solute (minority component) and a solvent (majority component).

• Common Usage: Aqueous solutions (water as solvent).

Solution Concentration

• Concentrated vs Dilute: Relative terms indicating solute amount; quantitative analysis provided by Molarity (M).

Solution Preparation

• Example provided: Preparing a solution based on molarity.

Concentration Calculations

• Example 1: Calculate the molarity of 75.6 g of acetic acid in 665 mL of vinegar.

• Example 2: Determine grams of CaCl2 in 250.0 mL of a 0.200 M calcium chloride solution.

Solution Dilution

• Concept: Diluting concentrated stock solutions to desired concentrations by adding solvent.

• Key Insight: Dilution does not change the total moles of solute.

• Dilution Equation: M1V1 = M2V2, applicable only to dilution of the same chemical.

Writing and Balancing Chemical Equations (Section 5.1)

Objectives

• Derive and balance equations from narrative reactions.

Chemical Equations

• Definition: Written representation of a chemical reaction; reactants on left, products on right.

• Balancing Requirement: Coefficients adjust to maintain atom equality.

Additional Equation Information

• Phases Notation: (s), (l), (g), (aq) indicating state of matter.

• Special Symbols: Indicate conditions like heat (∆).

Types of Chemical Reactions (Sections 4.5, 4.6, 5.4)

Objectives

• Define and classify common chemical reaction types.

Reaction Types

1. Precipitation: Products create a solid from two aqueous solutions based on solubility rules.

2. Acid-Base: Acid reacts with base to create salt and water; follows net ionic equations reflecting core reactants.

3. Gas Evolution: Reactions where gas is produced in an aqueous solution.

4. Oxidation-Reduction (Redox): Involves electron transfer; oxidation is loss, reduction is gain.

Predicting Chemical Reactions (Sections 5.2-5.3)

• Objectives: Predict products from precipitation and acid-base reactions.

Steps for Prediction

1. Write reactants.

2. Split into ions.

3. Switch partners.

4. Apply solubility rules to predict formation of precipitate.

Oxidation-Reduction Reactions (Sections 5.5-5.6)

Objectives

• Compute oxidation states and balance reactions in various conditions.

Assigning Oxidation States

• Rules for determining oxidation numbers; oxidation states must be assigned to track electron transfer during reactions.

Mass Percentage and Concentration Conversions

• Mass Percentage: Common in products; formulated as: mass percentage = (mass of component/total mass of solution) x 100%.

• Conversions: Used for practical applications, e.g., in consumer products.

Very Dilute Solutions: ppm and ppb

• Extremely low concentrations often represented as parts per million (ppm) or parts per billion (ppb).

Flint, MI Water Crisis Context

• Example highlighting the significant impact of chemical concentration on public health, illustrating ppm dangers.

Summary

• Considerable chemistry occurs in daily life, including in baking cookies.

• Understanding solutions and chemical reactions is crucial for both academic settings and real-life applications.