Lesson-4-Atomic-Mass-Empirical-Formula-and-Molecular-Formula
Page 1: Title and Instructor
Institution: Gardner College
Course: General Chemistry 1
Instructor: Mr. Sherwin Sinajonon
Page 2: Learning Objectives
Relative Atomic Mass: Explain the concept and significance.
Avogadro’s Number: Illustrate with examples.
Molar Mass: Determine for elements and compounds.
Mass Calculation: Calculate mass for a given number of moles of an element (and vice versa).
Page 3: Continuing Objectives
Percent Composition: Calculate from the formula of a compound.
Empirical Formula: Derive from the percent composition.
Molecular Formula: Calculate using the molar mass.
Page 4: Understanding Atomic Mass
Definition: Mass of a single atom expressed in atomic mass units (amu).
Atomic Mass Unit: Defined as 1/12 of a carbon-12 atom's mass, equating to about 1.66 × 10^(-27) kg.
Use in Chemistry: Important for understanding atomic and molecular scale behaviors.
Page 5: More on Atomic Mass
Atomic Mass vs. Weight: Often called atomic weight, it refers to the mass of an atom in amu.
Isotopes: Different forms of the same element with varying weights; example: Hydrogen has isotopes Deuterium and Tritium.
Page 6: Hydrogen Isotopes
Abundance of Isotopes:
1H: 99.985%
2H: 0.015%
Visual Representation: Depiction of hydrogen isotopes, their protons (P), and neutrons (N).
Page 7: Isotopic Mass of Hydrogen
Mass of Isotopes:
1H = 1.00784 amu
2H = 2.01410 amu
Average Mass: Average of the isotopes is calculated as 1.51097 amu.
Page 8: Isotopic Mass and Abundance Table
List of Elements:
Helium: 3.016029 amu (0.000137%) and 4.002603 amu (99.999863%)
Lithium, Carbon, Sulfur, Chlorine, Potassium: Isotopic masses and their corresponding abundances provided.
Page 9: Chlorine Isotopes Analysis
Chlorine Isotopes:
36Cl: 34.968853 amu (75.78%)
37Cl: 36.965903 amu (24.22%)
Objective: Determine relative atomic mass.
Page 10: Calculating Relative Atomic Mass
Steps:
Convert percent abundance to decimals (divide by 100).
Multiply atomic mass of isotopes by abundance.
Sum these products for the final relative atomic mass.
Page 11: Example for Chlorine Relative Atomic Mass
Reiteration of Isotope Details:
Confirm isotopes and abundance for clarity.
Page 12: Chlorine Isotope Summary
Isotopes and Their Properties Re-emphasized: Details of isotopes and material previously covered.
Page 13: Calculation of Chlorine's Relative Atomic Mass
Computation Steps:
26.499396 + 8.9531417 = 35.4525377 amu
Final Rounded Value: 35.45254 amu
Page 14: Lithium Isotopes Overview
Isotope Detail for Lithium:
6Li: 6.015122 amu (7.59%)
7Li: 7.016004 amu (92.41%)
Page 15: Calculation of Lithium’s Relative Atomic Mass
Detailed Steps:
Calculation breakdown for both isotopes provided for accuracy.
Page 16: Final Calculation for Lithium
Summed Result for Relative Atomic Mass:
From calculations: 6.9400370562 amu
Page 17: Definition of Formula Weight
Formula Weight: Summation of atomic weights of atoms in a compound.
Example with HCl: Calculation breakdown shared for HCl demonstrating method for finding formulation.
Page 18: Ca3(PO4)2 Formula Weight Calculation
Step-by-step computation example: Individual atomic weights for K, Mn, and O calculated leading to overall weight of the compound.
Page 19: H2O Formula Weight Calculation
Detailed atomic weight segmentation: For water involving individual contributions of H and O.
Page 20: Ca3(PO4)2 Continued Calculation
Heavy focus on detailed calculations: Steps traced out for clear understanding of molecular mass assessment.
Page 21: Explaining Molar Mass
Definition: Molar mass intrinsic to one mole of substance, presented in grams/mole.
Foundational relation to formula weight emphasized.
Page 22: Molar Mass in Context
Weight vs Molar Mass examples: Transition of amu values to gram values explained through examples with H2O and Ca3(PO4)2.
Page 23: Introduction to Avogadro's Number
Definition: Number of units (atoms, molecules, etc.) in one mole equals 6.022 x 10^23.
Importance in Stoichiometry touched upon.
Page 24: Units of Measurement in Avogadro's Number
Explanation of Units: Identifies the types of measurable units involved with Avogadro's number across different chemical contexts.
Page 25: Avogadro’s Number Calculation Example
Sample Table: Showcases various mole amounts for sodium atoms alongside corresponding weights and atom counts.
Page 26: Example Calculation with Molar Mass of NaOH
Contextual Problem: Compute moles of NaOH based on a given mass, tools for calculation indicated.
Page 27: Calculation Resolution of NaOH Moles
Explicit Steps Provided: Conversion from weight to mole values explained in a straightforward manner demonstrating successful computation.
Page 28: Ca3(PO4)2 Weight Calculation Problem
Given Data: Clearly stated values to compute the necessary mass of a specific mole amount provided for practice.
Page 29: Ca3(PO4)2 Calculation Solution
Problem Solving: Weight of substance calculated from number of moles reaffirms understanding of mole to gram conversions.
Page 30: CO2 Mole Calculation Introduction
Problem Statement: Weight given, molar mass specified, understanding of mole calculations primed for computation.
Page 31: Solving for Moles in CO2 Context
Mole Calculation Breakdown: Clear and direct computation leads to the mole amount derived from the weight provided.
Page 32: Molecule Calculation from Molar Data
Utilization of Avogadro's Number: Using the derived moles to calculate the total number of molecules in a given mass.
Page 33: Percent Composition Introduction
Definition and Importance: Understanding the percent composition allows insights into the makeup of compounds via mass comparisons.
Page 34: Percent Composition Formula
Mathematical Definition: Presentation of formulaic representation for calculating percent composition with examples.
Page 35: Water Percent Composition Calculation Example
Exploration of H2O: Stepwise approach to finding out the percent composition of elements in water underlined.
Page 36: Percent Composition Table
Visual Data Presentation: Further examples looking into percent compositions paving way for comprehensive understanding.
Page 37: Percent Composition for Ca(NO3)2
In-depth Calculation Steps: Each element's data presented distinctly illustrating contribution to total composition.
Page 38: Percent Composition Summary of Ca(NO3)2
Final Recap of Percentages: Clear summation of resulting percentages from earlier calculations emphasizing mastery of topic.
Page 39: Empirical vs. Molecular Formula Definition
Contrast Highlighted: Empirical formula as simplest atom ratio illustrated alongside molecular formula representing actual atom counts.
Page 40: Example Calculation for Empirical Formula
Hypothetical Scenario: Composition outlined for further analysis towards derivation of empirical formula.
Page 41: Steps to Find Empirical Formula
Step-by-step approach: Focus on deriving mole counts from a simplified sample value defined.
Page 42: Calculating Moles of Compound Elements
Mole Calculations Detailed: Introduction of molar conversions for all constituent elements.
Page 43: Mole Calculations Continued
Molar Findings: Final moles figure clarified reinforcing earlier format.
Page 44: Steps for Building Empirical Formula
Dividing the smallest number of moles: Crucial steps detailed explaining simplification process.
Page 45: Empirical Formula Resolution Steps
Substituting for Smallest Quotients: Clear directives supporting methodology on achieving empirical formula successfully outlined.
Page 46: Completing Empirical Formula Steps
Final Formula Construction: Ensuring incorporation of whole number ratios in final implications.
Page 47: Determining Molecular Formula Steps
Methodology Outlined: Key procedures for reaching molecular formula shared.
Page 48: Empirical and Molecular Formula Example Problem
Heuristic Breakdown: Compound characteristics outlined for computational practice.
Page 49: Empirical Formula Weight Calculation
Molarity Figures Provided: Individual contributions from each elemental composition aligned for computation.
Page 50: Simplifying Mole Ratios for Empirical Formula
Final Ratios Established: Final forms of elements derived fulfilling empirical expectations.
Page 51: Compilation of Empirical Formula Weight
Weight Compilation Approach: Each computation focused upon to formulate a coherent final weight.
Page 52: Derivation of Molecular Formula from Weight
Finding the Multiple: Important variable representations established along the path to final formula.
Page 53: Final Molecular Formula Presentation
Finalizing Chemical Formulation: Conclusively pointing towards the derived molecular structure.
Page 54: Additional Empirical Formula Problems
Problem Presentations: Assigned tasks around percentage rules and molar conversions to drive understanding.
Page 55: Sulfur and Iron Compound Problem
Complexity Building: Challenge-oriented task setup for deeper exploration of empiricals.
Page 56: Compound Including Potassium and Oxygen
Diversity in Element Examples: Purpose of this exercise teaches varied approaches in empirical formula deductions.
Page 57: Phosphorus and Oxygen Ratio Formula Exploration
Focused Chemical Investigation: Reliable problems designed to foster skill-building in related applications.
Page 58: Empirical Formula Reinforcement
Finalized Hydrocarbon Example: Calculative tasks lead right back into empirical formulations for completion.
Page 59: Summary of Key Points (Part 1)
Atomic Mass Unit Importance: Defined basis for unified measuring system across atomic levels.
Relative Atomic Mass Methodology: Stepwise directives revisited to ensure foundational knowledge retention established.
Page 60: Summary of Key Points (Part 2)
Formula Weight Understanding: Core elements of formulas leading to weight aggregations clarified in sync with molecular principles.
Page 61: Summary of Key Points (Part 3)
Emphasis on Molar Mass: Integral connections between formula weight to practical gram representations.
Avogadro’s Number Utility: Continues to reign as fundamental in quantitative chemistry analysis.
Page 62: Summary of Key Points (Part 4)
Percent Composition Overview: Central to chemical mixtures and foundational understanding solidified.
Page 63: Summary of Key Points (Part 5)
Final Contrast of Empirical and Molecular Formula: Distinction between formulaic representations made clear across various topics.
Page 64: References (Part 1)
Citing educational materials and resources utilized for gathering informational content.
Page 65: References (Part 2)
Further details on resources and references listed to support document's educational integrity across topics.