Chapter 7.1 - 7.7 Chemical Reactions
(NH₄)₂SO₄ + Pb(NO₃)₂ → NH₄NO₃ + PbSO₄
(NH₄)₂SO₄ + Pb(NO₃)₂ → 2 NH₄NO₃ + PbSO₄
(NH₄)₃PO₄ + AgNO₃ → NH₄NO₃ + Ag₃PO₄
(NH₄)₃PO₄ + 3 AgNO₃ → 3 NH₄NO₃ + Ag₃PO₄
CaSiO₃ (Find # of each element)
1 calcium, 1 silicon and 3 oxygen atoms
Ca(OH)₂ (Find # of each element)
1 calcium, 2 oxygen and 2 hydrogen atoms
balancing eqs. 3:
Change the single elements first, write out like this
Single Displacement
Cl2 + KI --> KCl + I2
5 Cr(C₂H₃O₂)₆
Cr:5, C: 60, H: 90, O: 60
C₃H₈ + O₂ → CO₂ + H₂O
C₃H₈ +5 O₂ → 3 CO₂ + 4 H₂O
2 N₂O₅
Dintrogen Pentoxide
5 Fe₂(C₂O₄)₃
Fe:10, C:30, O:60
Double Displacement
HCl + NaOH --> NaCl + H2O
Balancing reactions with Polyatomic Ionic Compounds
If the same polyatomic ion is on both sides of the reaction, then it is counted as if it were an element.
Conservation of Mass in Chemical Reactions
In reaction equations, no atoms can be created or destroyed; atoms can only be rearranged in the process.
The subscript that immediately follows an atomic symbol shows what?
It shows how many of that atom is present in the formula unit.
Mg₃(PO₄)₂
Magnesium Phosphate
3 Mn₂ O₅
Manganese (V) Oxide
How many atoms are in Mg(OH)₂
Mg: 1 atom (1 magnesium atom)
How many atoms are in 3 Mg(OH)₂
Mg: 3 atoms (3 magnesium atoms)
6 (NH₄)₂H₂PO₄
N:12, H:60, P:6, O:24
Decomposition
Ni(ClO3)2 --> NiCl2 + O2
The second part of the reactants to products transformation
Once the atoms are in new arrangement, new substances (the products) exist.
Single Displacement
One element trades places with another element in a compound.
Decomposition
One substance breaks down into two or more substances.
K₃PO₄
Potassium Phosphate
Reactants → Products
Reactants yield Products
SO₃
Sulfur Oxide
The first part of the reactants to products transformation
The atoms of the reactants become rearranged (this is when the existing bonds break and new bonds form).
Importance of the Law of Conservation of Mass in Chemical Reactions
The number of atoms on the left side must equal the number of atoms on the right side.
what is a phase?
The pyhsical state of an elemet (aq),(s),(g) etc
Combustion
The reaction that reacts with oxygen to produce CO2, H2O, and fire.
States of Matter in Chemical Reactions
The state of matter for each reactant and product is often presented in a reaction equation.
Products
The substances made out of atoms that are formed in a reaction.
acid base neutralization
This is a special kind of double displacement reaction that takes place when an acid and base react with each other. The H+ ion in the acid reacts with the OH- ion in the base, causing the formation of water. Generally, the product of this reaction is some salt and water: HA + BOH ---> H2O + BA
single displacement
This is when one element trades places with another element in a compound. These reactions come in the general form of: A + BC ---> AC + B
double displacement
This is when the anions and cations of two different molecules switch places, forming two entirely different compounds. These reactions are in the general form: AB + CD ---> AD + CB
Synthesis
Two substance combine into one substance.
Definition of: (l)
pure liquid
Definition of: H₂O(l)
pure liquid water
Definition of: (s)
solid
Definition of: Cu(s)
solid copper metal
Balancing Reactions
the reactants side (left side) have to same amount of atoms of each element as the Products (right side)
2 H₂ + O₂ → 2 H₂O
use this in the following questions
balancing eqs. 2:
we can only change the coefficients
CHO
when carbon, hydrogen and oxygen are the elements, then you always balance C first, H second and O last
when there are reaction coefficients, how do you count the atoms?
when counting atoms, reaction coefficients distribute to all atoms in the formula unit
Counting Atoms in Formulas and Reaction Equations
with and without prentheses
what is the mole ratio of H₂ to O₂?
2:1
what is the mole ratio of H₂ to H₂O?
2:2 or 1:1
If you need 100 moles of water to serve everyone, then how many moles of Hydrogen will you need?
100 H₂ + 50 O₂ → 100 H₂O
what is the mole ratio of O₂ to H₂O?
1:2
Al + Cu(NO₃)₂ → Cu + Al(NO₃)₃
2 Al + 3 Cu(NO₃)₂ → 3 Cu + 2 Al(NO₃)₃
C₈H₁₈ + O₂ → CO₂ + H₂O
2 C₈H₁₈ + 25 O₂ → 16 CO₂ + 18 H₂O
H₂ + O₂ → H₂O
2 H₂ + O₂ → 2 H₂O
How many Phosphorus atoms are in 2(NH₄)₃PO₄?
2 Phosphorus atoms
How many atoms of P in 2Na₃PO₄(aq)?
2 Phosphorus atoms
Al₂(SO₃)₃ (Find # of each element)
2 aluminium, 3 sulphur and 9 oxygen atoms
2 H₂ + O₂ → 2 H₂O
2 moles of hydrogen + 1 mole of Oxygen yields 2 moles of water
NH₄NO₃ (Find # of each element)
2 nitrogen, 4 hydrogen and 3 oxygen atoms
How many Hydrogen atoms are in 2(NH₄)₃PO₄?
24 Hydrogen atoms
(NH₄)₃PO₄ (Find # of each element)
3 nitrogen, 12 hydrogen, 1 phosphorous and 4 oxygen atoms
Al + O₂ → Al₂O₃
4 Al + 3 O₂ → 2 Al₂O₃
Na + O₂ →Na₂O
4 Na + O₂ → 2 Na₂O
1 mole = ? atoms
6.022x10²³ atoms
how many Oxygen atoms are in 2(NH₄)₃PO₄?
8 Oxygen atoms
Combustion
? + O2 --> CO2 + H2O
Mole Ratios and Conversions
???
mole to mole conversions
????
Synthesis
A + B --> AB
Single Displacement
A + BC --> B + AC
decomposition
A _______ reaction is when a complex molecule breaks down to make simpler ones. These reactions come in the general form: AB ---> A + B
combustion
A _______ reaction is when oxygen combines with another compound to form water and carbon dioxide. These reactions are exothermic (produce heat).
synthesis
A _______ reaction is when two or more simple compounds combine to form a more complicated one. These reactions come in the general form of: A + B ---> AB
Double Displacement
AB + CD --> CB + AD
Decomposition
AB --> A + B
(NH₄)₂SO₄
Ammonium Sulfate
metathesis
Another name for the double displacement reaction
Reactant
Any substance made out of atoms that undergoes a chemical reaction.
Synthesis
C + H2 --> CH4
How many atoms are in CO₂
C:1 atom (1 carbon atom)
Combustion
CH2 + O2 --> CO2 + H2O
CH₄ + O₂ → CO₂ + H₂O
CH₄ + 2 O₂ → CO₂ + 2 H₂O
Double Displacement
When the positive ion of one compound replaces the positive ion of another to form two new compounds.
differences of the reactant and of the product
When the reaction takes place, the reactant transforms into the product. the product and the reactant are different substances, which have different composition, structure and properties.
How many atoms of each element are in the formula and what is the name of the formula ?
answer the following questions
Definition of: NaCl (aq)
aqueous sodium chloride, which is sodium chloride dissolved in water which is salt water.
Definition of: (aq)
aqueous solution (a solution where water is the solvent)
Strategy to balance equations
balance the elements starting with those who appear the least and finishing with the most abundant.
balancing eqs. 1:
charges must be the same
B₂O₃
diboran trioxide
Definition of: (g)
gas
Chemical Reaction
is a chemical change, which is any change in matter that results in the formation of a new substance. Which is a change in identity.
the mole
is the unit of measurement that is used in all substances that are in a chemical reaction.
Reaction Coefficient
it is the number written before a formula in a reaction equation.
The subscript outside those parentheses shows what?
it shows how many atoms each of those elements inside the parentheses are present.
balancing eqs. 4: When we can only make it work with a fraction, how do we write it like that? we cant have fractions!
multipyl the fraction ofo the denomonator to every term including its own(cancels out denomonator)
Definition of: O₂(g)
oxygen gas