chemical reactions lab

Introduction What is chemical change? Chemical change is the alteration of a substance into one or more different substances with different properties (also called chemical reaction). The four different types of chemial reations are synthesis, decomposition, single displacement, and double displacement. Synthesis is when atoms and/or molecules combine to form larger molecules. Decomposition is when a large molecules are split into elements or smaller molecules. Single Displacement has an element and a compound as reactants and one element replaces another element to form a new compound. Double displacement has two compounds as reactants and the elments in each compound exchange places. The way to test the presence of oxygen gas is by putting a glowing splint of a match in a substance that may contain oxygen. The evidence resercher look for oxygen gas is if the splint lights up. The way to test the presence of hydrogen gas is by using a burning splint. The evidence resercher look for hydrogen gas if the gas makes a “popping” sound. The way to test the presence of carbon dioxide gas is its reaction with limewater. The eveidence resercher look for carbon dioxide gas is if the reaction with the limewater forms a milky-white precipitate. The way to tell if a chemical change has occurred are colour change, light formed or has been seen, precipitate formed, and/or change in temperature.
Purpose: The purpose of this lab was to determine the four different types of chemical reactions and able to indicate the chemical reactions in an experiment.
Hypotheses: I hypothesized that reaction 1 would be a synthesis reaction. I hypothesized that reaction 2 would be a single displacement reaction. I hypothesized that reaction 3 would be a double displacement reaction. I hypothesized that reaction 3 would be a decomposition reaction.
Procedure: Two specific precautions that must be considered for students safety are to handle the lighters with great responsibility in front of gas