Luokat: Kaikki - equations - oxidation - reactions - atoms

jonka Linda Paea 7 vuotta sitten

351

What are the products of a chemical reaction?

Chemical reactions involve the rearrangement of atoms to form new substances, adhering to the Law of Mass Conservation, which states that the types and numbers of atoms must remain the same on both sides of the reaction equation.

What are the products of a chemical reaction?

What are the products of a chemical reaction?

Redox reactions

Reduction
losing oxygen, gaining hydrogen; decrease oxidation number, increase electrons
Oxidation
gain oxygen, remove hydrogen; increase oxidation number, decrease electrons
Fe + O => FeO

This is also known as Rusting

rearranging atoms => new substance formation

number of atoms in reactants = number of atom in products
coefficients number of molecules for reaction (completed)
subscripts number of atoms in molecule => atomic properties

MISCONCEPTION: that subscripts and coefficients are interchangeable

Processes taking occurring when Aboriginal & Torres Strait Islanders detoxify food

Cycad seeds
cycasin toxin broken down and removed

Neutralisation

A.A.W.S
Acid + Alkail => Water + Salt

HCl + NaOH => H20 + NaCl

B.A.W.S
Base + Acid => Water + Salt

Acid - Base titrations

AH + BOH => AB +H20

M.A.S.H
Metal + Acid => Salt + Hydrogen

Sn + 2HCl => SnCl2 + H2

C.A.W.C.S
Carbonate + Acid => Water + Carbon Dioxide + Salt

CuCO3 + 2HCl => CuCl2 + H2O + CO2

Precipitation

When solutions mix together to form a solid
Lead Nitrate (l) + Potassium Iodide (l)

Lead Iodide(s) + Potassium Nitrate (l)

Rearrangement of atoms (Chemical Reaction)

Obeys the Law of Mass Conservation

Balance Equations
Types and number of atoms are the same on each side of the equation

Separates Compounds

Double Displacement

When a more reactive element takes the place of a less reactive one in a compound
AB + CD => AD + BC

The cations and anions switch elements

Nature of the product, determined by solubility table
2 compounds to start; 2 compounds produced

Higher Temperature, more kinetic energy (move faster), increase in the rate of reaction

Chemical Changes

MISCONCEPTION: Dissolution is a physical change (state change) Students consider solid dissolved in liquid due to the solid 'disappearing'.
Production of odour
Formation of gas/ precipitate
Precipitate: does not dissolve, solid at room temperature
Heat/Light released/ absorbed
Colour changes

Synthesis

Combination of 2 reactants, only one product

Decomposition

Breaking down of a compound into its simple starting reactants (into elements)
Thermal

CaCO3 => CaO + CO2 (Heat Energy)

Electrolysis

NaCl => Na + Cl )Electrical Energy)

Bleach is made by the electrolysis of sale water

Light

AgBr => Ag + Br (Light Energy)