1. CHEMICAL REACTIONS

2. Chemical Reactions INVESTIGATION ONE

3.  Chemical compounds are formed when two or more elements combine.  H ₂ + O  H₂O (water)  Na + Cl  NaCl ( Sodium Chloride – Salt) CHEMICAL COMPOUNDS

4.  Elements are held together by chemical bonds.  Two Types of Chemical Bonds  Ionic bonds are formed by positive and negative ions that are attracted together resulting in the loss or gain of electrons  Covalent bonds are formed between Carbon atoms and another element and no electrons are gained or lost. CHEMICAL BONDS

5.  When two or more compounds interact a chemical reaction can occur  The chemical compounds that interact are called reactants  The substances that form from their interactions are called products CHEMICAL REACTIONS

6.  Reactants and Products can be written in the form of an equation called a chemical formula  Reactants and Products are separated by (  ) (yield)  Reactant + Reactant  (yield) Product (s)  NH ₄ OH + HCL  H ₂ O + NH ₄ CL + Heat  Ammonium hydroxide + hydrochloric acid yields water + ammonium chloride+ heat CHEMICAL FORMULAS

7.  Single elements, new compounds, and heat all can be products of a chemical reaction  Measuring the starting temp ending temp determines the amount of heat and products produced PRODUCTS

8.  In a chemical reaction, as the amount of reactants increases the amount of the products produced also increases. RELATIONSHIP BETWEEN REACTANTS AND PRODUCTS

9. Chemical Reactions INVESTIGATION TWO

10.  During a chemical reaction the bonds that hold chemical compounds together break and reform in different arrangements when they interact to form products BONDS IN CHEMICAL REACTIONS

11.  When all of the reactants are used in a chemical reaction they no longer are present in their original form  All of the atoms from the reactants are found in the products  The atoms are converted from a reactant to a product REACTANTS IN CHEMICAL REACTIONS

12.  The converting of reactants to products is referred to as the Law of Conservation of Matter  Matter is not created or destroyed just simply changes (converted) form LAW OF CONSERVATION OF MATTER

13.  Sometimes some reactants are present in higher amount than others  The one that has a lesser amount is completely used up in the reaction  At this point the chemical reaction stops and the other reactant remains unreacted  Mg + 2HCl  MgCl ₂ + H ₂ REACTANTS

14.  Reactants must be present in the reaction in equivalent amounts to produce the maximum amount of all products AMOUNT OF REACTANT AFFECTING THE AMOUNT OF PRODUCTS

15.  No matter is lost from a chemical reaction even is the reactants are present in amounts that are not equivalent.  Every atom of every reactant can be found in either the products or in the reactants that are not consumed LAW OF CONSERVATION OF MATTER AND CHEMICAL REACTIONS

16. INVESTIGATION THREE

17.  As the reactants interact they are consumed at the same time that the products are formed.  Since the products come from the reactants and the rate at which the reactants are consumed is equal to the rate that the products are formed. CHEMICAL REACTIONS

18.  The rate at which a reactant disappears or a product is produced can be measured to get the rate of the reaction  Scientist can measure the absorbance of a specific wavelength to determine the rate of the reaction  Spectrophotometer measures the absorbance of different wavelengths  Wavelength is measured in nanometers RATE OF A REACTION

19.  In order to affect the rate of a reaction a catalyst can be added  A catalyst is neither a reactant nor a product because it is not produced or consumed.  CH₃COCH₃ + I₂  (HCL)  CH₃COCH₂I + HI  HCL = catalyst SPEEDING UP A REACTION

20.  As the amount of reactant increases, the rate of the reaction increases.  As the rate increases, this can be measured as an increase in the rate of disappearance if the reactants and an increase in the production of products.  Therefore the more reactants added to a reaction, the more products that will be produced. RELATIONSHIP BETWEEN REACTANTS, PRODUCTS, AND THE RATE OF THE REACTION