Chemical formulas
Write the unbalanced formula equation from the following word equations
A. iron combines with sulfur - Fe + S > FeS B. Calcuim carbonate breaks down into calcium - CaCO3 > CaO + CO2 C. Water and carbon dioxide - CO2 + H2O > H + HCO3- D. Carbon monoxide burns in oxygen > 2CO + O2 > 2CO2
What are special symbols in chemical equations
(aq) - dissolved (l) - liquid (S) - solid (G) - gas
Name three out of five signs that a chemical change may have taken place
1. Solid separates from a liquid mixture of chemicals 2. Bubbles of gas form or explosions occur 3. Color of substance change
3 steps to writing a chemical formula
1. Write a word equation 2. Put into formula equation 3. Balance atoms if necessary
Understand 5 ways to determine a Chemical reaction
1.A solid separates from a liquid mixture of chemicals 2. Bubbles of gas form or an explosion of gases occurs 3. Color of substance changes-usually permanent 4. Temperature of mixture of chemicals change 5. Light, sound, or another energy is produced.
Chemical thermodynamics
Classifying reactions by how energy moves in and out of the process
What is a balanced chemical equation
Coeffiencents are placed in front of formula to balance
Know the four types of reaction
Composition Reaction / Synthesis Decomposition Reaction Single-Replacement Reaction Double-Replacement Reaction
Explain how you can determine each
Double replacement - two compounds switch cations and anions with each other Single replacement - one element replaced by another element Decomposition - break apart of decompose substance Synthensis - combine two or more substances
Explain law of conservation of energy
Energy cannot be destroyed in a system
Products
Formulas after arrow
Reactants
Formulas before arrow
Difference between exothermic and endothermic reactions
Give of large quantites of heat = exo Reactions that absorb thermal energy = endo
Mesuarement used
Joules
Laws of thermodynamics
Law of conservation of energy
Catalyst
Not a reactant nor product doesn't change
Balanced equation
Pb + O2 > PbO = 2 Pb + O2 > 2PbO
Arrow in chemical equations shows
Precipitate , gaseous byproduct
What do we call a solid product that settles out of a solution following a reaction
Precipitate reaction
What are the products and reactants of a chemical equation
Reactants - formula before arrow Product - formula after arrow
Know symbols for state of matter of reactants and products
Reactants = formulas before arrow Products = formulas after arrow
Precipitate
Solid product that settles outside the solution
Compounds use subscripts, formulas use
Substances
Why do we use chemical formulas
Tell us chemicals present before and after
Key to chemical reactions
Total amount of matter present before a reaction must equal the total amount of matter present after the reaction
Double replacement
WX + YZ > WZ + YX
Single replacement
XY + Z > ZY + X
Decomposition
XY > X + Y
Synthesis
Zn + S = ZnS
