Honors - Unit 5 - Chemical Reactions Flashcards
Le Chatlier’s Principle
Symbols used in writing chemical equations
Definition of a balanced chemical equation:
no atoms are lost or gained
the number of reacting atoms is equal to the number of product atoms
Law of Conservation of Mass
Mass is neither created or destroyed during a chemical reaction - it is conserved.
Mass Reactants = Mass Products
Subscript
Small numbers to the lower right of chemical symbols. Represent the number of atoms of each element in a molecule.
O₂
Coefficients
The large numbers in front of chemical formulas. Represents the number of molecules of the substance.
2Al
Diatomic Molecules
If these elements appear by themselves in an equation, the must be in pairs with the subscript 2.
(H₂, N₂, O₂, F₂, Cl₂, Br₂, I₂)
Reactants
Substances being mixed in a chemical reaction. The left side of the equation.
Products
Substance(s) being made. Right side of the equation.
Synthesis or Combination
Two or more elements combine to make one product.
A + B –> AB
Decomposition Reaction
One reactant breaks down into two or more elements.
AB –> A + B
Single Replacement
An element and a compound are located on each side of the equation. The Activity Series must be checked to determine if the reaction will occur. If the reaction occurs, the element on the reactant side switches with the similarly charged ion within the compound on the reactant side.
A + BC –> AC + B
Double Displacement
There are two compounds on each side of the equation. During a DD Reaction the positively charged cations in each compound switch places. Also known as Precipitate Reaction. For the reaction to occur a precipitate must be formed. The solubility rules or table are used to confirm this.
AB + CD –> AD + CB
Precipitate
Formation of a solid in a solution.
Combustion
Any compound formed from only Carbon an Hydrogen (fuel) added to Oxygen to produce Carbon Dioxide and Water.
Predict the products and write a balanced equation from the following word statement:
Methane (CH₄) plus Oxygen Gas forms:
How to PREDICT PRODUCTS of the 4 Main Types of Chemical Reactions.
Predict the products of and write a balanced equation from the following word statement:
Methane (C3H8) reacts with Oxygen gas to form __________.
Write a chemical equation from the following word equation:
Magnesium reacts with oxygen to form magnesium oxide.
2Mg + O₂ –> 2MgO
Write a chemical equation from the following word equation:
Magnesium reacts with aluminum chloride to form magnesium chloride and aluminum.
3Mg + 2AlCl₃–> 3MgCl₂ + 2Al
Write a chemical equation from the following word equation:
Sodium reacts with fluorine to form sodium fluoride
2Na + F₂–> 2NaF
Write a chemical equation from the following word equation:
Lithium chloride reacts with magnesium nitrate to form lithium nitrate and magnesium chloride.
2LiCl + Mg(NO₃)₂ –> 2Li(NO₃) + MgCl₂
Write a chemical equation from the following word equation:
Water decomposes into hydrogen gas and oxygen gas:
2H₂O → 2H₂ + O₂
Predict the products of and write a balanced equation from the following statement:
C₄H₆ + O₂ →
2C₄H₆ + 7O₂ →4CO₂ + 6H₂O
Combustion
Predict the products of and write a balanced equation from the following statement:
Mg + I₂ →
Mg + I₂ →MgI₂
Synthesis
Predict the products of and write a balanced equation from the following statement:
CuCl₂ + H₂S →
CuCl₂ + H₂S →CuS + 2HCl
Double Replacement
Predict the products of and write a balanced equation from the following statement:
HCl + Zn →
2HCl + Zn →ZnCl₂ + H₂
Single Replacement
Predict the products of and write a balanced equation from the following statement:
H₂O₂ →
H₂O₂ → H₂ + O₂
DECOMPOSITION
Balance the following chemical equation:
__Al₂(SO₄)₃ + __Ca(OH)₂ → __Al(OH)₃ + __CaSO₄
Al₂(SO₄)₃ + 3Ca(OH)₂ → 2Al(OH)₃ + 3CaSO₄
Balance the following chemical equation:
__C₂H₆ + __O₂ → __CO₂ + __H₂O
2C₂H₆ + 7O₂ → 4CO₂ + 6H₂O
Balance the following chemical equation:
__C + __O₂ → __CO₂
1C + 1O₂ → 1CO₂
C₄H₆ + O₂ →
2C₄H₆ + 7O₂ →4CO₂ + 6H₂O Combustion
Mg + I₂ →
Mg + I₂ →MgI₂ Synthesis
CuCl₂ + H₂S →
CuCl₂ + H₂S →CuS + 2HCl Double Replacement
NaOH + HClO₄ →
NaOH + HClO₄ →NaClO₄+ H₂O Double Replacement
HCl + Zn →
2HCl + Zn →ZnCl₂ + H₂ Single Replacement
Na + MgCl₂ →
2Na + MgCl₂ →2NaCl + Mg Single Replacement
CaCl₂ + K₂CO₃ →
CaCl₂ + K₂CO₃ →CaCO₃ + 2KCl Double Replacement
K + Cl₂ →
2K + Cl₂ →2KCl Synthesis
How would temperature and pressure affect the equilibrium of the following reaction?
N2 + 3H2 ⇔ 2NH3 + heat
How would removing ammonia, NH3, affect the equilibrium of the following reaction?
N2 + 3H2 ⇔ 2NH3 + heat
How does a reaction at equilibrium shift when more reactants are added?
Reaction shifts to the right to make more product.
How does a reaction at equilibrium shift when reactants are removed?
Reaction shifts to the left to make more reactant.
How does a reaction at equilibrium shift when more products are added?
Reaction shifts to the left to make more reactant.
How does a reaction at equilibrium shift when products are removed?
Reaction shifts to the right to make more product.
What happens to an endothermic reaction when temperature is increased?
Heat is a reactant, so the reaction will shift to the right to make more product.
What happens to an endothermic reaction when temperature is lowered?
Heat is a reactant, so the reaction will shift to the left to make more reactant.
What happens to an exothermic reaction when temperature is increased?
Heat is a product, so the reaction shifts to the left to make more reactant.
What happens to an exothermic reaction when temperature is lowered?
Heat is a product, so the reaction shifts to the right to make more product.
What happens when the pressure of a reaction at equilibrium is increased?
It depends if there are gases present. If there ARE gases present, reaction will shift to the side with the lower number of moles of gas.
What happens when the pressure of a reaction at equilibrium is increased?
It depends if there are gases present. If there ARE gases present, reaction will shift to the side with the greater number of moles of gas.
