Every year, the National High School Exam has been increasing the level of its questions, and with Chemistry it is no different. As this area of knowledge always brings a lot of fear to students, this text seeks to guide them on the most demanding topics.
In addition to knowing what has been most demanded of Chemistry in recent tests, it is essential to be aware that one of the competences demanded by Enem is knowing how to relate the subjects. As many topics in Chemistry are linked to each other and to other areas of knowledge, it is necessary for the student to know as much as possible about chemical aspects and concepts.
See now the most important Chemistry subjects for Enem:
1. General chemistry
properties of matter (density, melting and boiling points);
Physical and chemical phenomena
Separation of mixtures (filtration, simple distillation, fractional distillationdecant, flotation etc.)
Mol (amount of matter, Avogadro constant);
Stoichiometry (calculations involving excess and limiting, purity, yield in chemical reactions)
Equation Balancing
Chemical bonds (ionic, covalent, metallic)
Atomistic (elementary particles of the atom, atomic similarity, eletronic distribution)
2. Inorganic chemistry
The) Inorganic Functions
Acids
Bases
Oxides
salts
B) Inorganic Reactions
Neutralization
double exchange
3. Physicochemical
The) Solutions
Solubility of solute in solvent
Relationship between solubility and temperature
Concentration in quantity of matter (molarity)
Dilution
Titration
B) Electrochemistry
Oxidation and reduction
NOX
Stacks
metal corrosion
Electrolysis
ç) Chemical balance
chemical balances
Factors that alter a chemical balance
Ionization constant
pH and pOH
Solubility equilibrium constant (Kps)
d) thermochemistry
Combustion enthalpy
Types of reactions in thermochemistry
Calculating the enthalpy of a chemical reaction
and) Radioactivity
Types of radiation (alpha, beta and gamma)
Half life
Fusion and fission nuclear
4. Organic chemistry
The) Organic functions
Hydrocarbons (alkane, alkene, alkyne, alkadiene, aromatic etc.)
Oxygenated functions (alcohol, aldehyde, ketone, carboxylic acid, ether, ester etc.)
Nitrogen functions (amines, amides, nitro compounds, nitriles, etc)
Other functions (organic halides, sulfonic acids etc.)
B) organic reactions
Complete and incomplete combustion
Transesterification Reaction
saponification reaction
5. Environmental Chemistry
the ozone layer
Solar energy
Greenhouse gases
The three "Rs" policy: reduce, reuse and recycle
Global warming
Water pollution
Atmospheric pollution
Acid rain
Principles of Green Chemistry
By Me. Diogo Lopes Dias
Source: Brazil School - https://brasilescola.uol.com.br/quimica/conteudos-quimica-para-enem.htm