University:
Felician University
Course:
CHEM-001 | Basic Chemistry
Academic year:

2019
Views:

486

Pages:

10
Author:

Clint W.

Decomposition A single compound undergoes a reaction that produces 2 or more simpler substances.  (NH4)2Cr2O7  N2 + 4H2O + Cr2O3 electricity 2H2O(l)  2H2(g) + O2(g) Electrolysis– the decomposition of a substance by an electric current. Decomposition CLUE: 1 Reactant falls apart into 2 or more Products Decomposing Dead Body One body falls apart into many products Decomposition Exceptions •Carbonates and chlorates are special case decomposition reactions that do not go to the elements. • Carbonates (CO32-) decompose to carbon dioxide and a metal oxide • Example: CaCO3  CO2 + CaO • Chlorates (ClO3-) decompose to oxygen gas and a metal chloride • Example: 2 Al(ClO3)3  9 O2 + 2 AlCl3 • There are more… but we will not explore those in Chemistry I •An example of decomposition reaction is an air bag. Automobile air bags inflate rapidly as sodium azide pellets decompose. A device that can provide and electric signal to start the reaction is packaged inside air bags along with sodium azide pellets 2NaN3  2Na + 2N2 sodium azide sodium nitrogen gas Single Replacement aka single displacement CLUE: one of the two reactants is an element AND one of the two products is another element. Single Replacement •A metal can replace a metal (+) OR a nonmetal can replace a nonmetal (-)   (remember the cation always goes first!) (if A is a metal) OR (if A is a nonmetal) Ex. When H2O splits into ions, it splits into H+ and OH(not H+ and O-2 !!) Mg + magnesium 2 H2O  water (H-OH) Mg(OH)2 + H2 magnesium hydroxide hydrogen gas