1 / 10

Understanding Chemical Equations and Reactions: A Comprehensive Guide

Discover the fundamentals of chemical reactions, equations, and key symbols used. Learn about reactants, products, hints of reactions, and writing equations correctly. Explore examples and understand the limitations of equations in predicting reactions.

emmam
Download Presentation

Understanding Chemical Equations and Reactions: A Comprehensive Guide

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chemical Equations and Reactions Describing Chemical Reactions

  2. Chemical Reactions • when a substance changes identity • Reactants - original • Products - resulting • Reactants  Products • Law of Conservation of Mass - mass is never created or destroyed, just rearranged • total mass of reactants = total mass of products

  3. Chemical Reactions • chemical equation • Written form of a chemical reaction • uses symbols and formulas

  4. Hints of Chemical Rxn • heat or light • can also happen with physical changes • gas bubbles • means a gas is product • precipitate • solid is being created • color change

  5. Writing Chemical Equations • Most pure elements - write symbol • Diatomic molecules - found in pairs when not bonded to other elements • HOFBrINCl! H2, O2, F2, Br2, I2, N2, Cl2 • Other exceptions • sulfur: S8 • phosphorus: P4

  6. yields (produces) reversible Things above arrow show Special requirements: or heat: heated MnO2 or Pt: catalyst 25°C :specific Temp requirement 2 atm: specific Pressure after a formula: (s) solid (l) liquid (aq) aqueous: dissolved in water (g) gas Symbols Used in Equations

  7. Coefficients 4Fe(s) + 3 O2(g) 2 Fe2O3(s) • Whole numbers in front of formula • Distributes to numbers of atoms in formula • specifies the number of moles in the reaction • used to balance the equation

  8. Word Equations • uses names instead of formulas • helps you to write formula equation

  9. Example • Description: Solid sodium oxide is added to water at room temperature and forms sodium hydroxide. • Word Equation: sodium oxide + water  sodium hydroxide • Formula Equation: Na2O + H2O  NaOH

  10. Equations cannot tell us: • if the reaction will actually occur • depends on many factors affecting energy • the speed (rate) of the reaction • depends on chemical kinetics • can be altered by temperature, surface area, addition of a catalyst • can be very slow, almost unnoticeably • how the bonding actually changes • formula may not clearly show bonding

More Related