Vietnam: What is a molecular formula? What arre the guidelines for writing a molecular formula? What is the grade at which students study and learn about the molecular formula in the Chemistry curriculum?

What is a molecular formula? What arre the guidelines for writing a molecular formula?

A molecular formula is a chemical expression indicating the number and type of atoms present in a molecule of a chemical substance. It provides detailed information about the composition of a substance.

*Examples:

Water (H₂O): Consists of 2 hydrogen atoms (H) and 1 oxygen atom (O).

Glucose (C₆H₁₂O₆): Contains 6 carbon atoms (C), 12 hydrogen atoms (H), and 6 oxygen atoms (O).

Table salt (NaCl): Has 1 sodium atom (Na) and 1 chlorine atom (Cl).

>>How to write a molecular formula

To write a molecular formula, we use the chemical symbols of the elements and subscript numbers to indicate the number of atoms of each element in the molecule.

Chemical symbol: Each chemical element has its own symbol (e.g., H for hydrogen, O for oxygen, C for carbon).

Subscript number: This number indicates how many atoms of the element are in the molecule. If there is only one atom, the number 1 is usually omitted.

*Examples:

Carbon dioxide (CO₂): Has 1 carbon atom and 2 oxygen atoms.

Methane (CH₄): Contains 1 carbon atom and 4 hydrogen atoms.

Molecular formula and empirical formula

Empirical formula: Indicates the simplest ratio of atoms in the molecule.

Molecular formula: Provides the exact number of atoms of each element in the molecule.

*Examples:

Glucose (C₆H₁₂O₆): The empirical formula is CH₂O, but the molecular formula is C₆H₁₂O₆.

*Note: The above information is for reference only./.

What is a molecular formula? What arre the guidelines for writing a molecular formula? What is the grade at which students in Vietnam study and learn about the molecular formula in the Chemistry curriculum? (Image from the Internet)

What is the grade at which students in Vietnam study and learn about the molecular formula in the Chemistry curriculum?

Under Section 5 of the General education program in Chemistry issued with Circular 32/2018/TT-BGDDT, the requirements for 11th-grade Chemistry are as follows:

GENERAL ORGANIC CHEMISTRY

Molecular formulas of organic compounds

- State the concept of molecular formulas of organic compounds.

- Use mass spectrometry (MS) results to determine the molecular weight of organic compounds.

- Formulate the molecular formula of organic compounds from elemental analysis and molecular weight data.

Chemical structure of organic compounds:

- Present the content of the chemical structure theory in organic chemistry.

- Explain the phenomenon of isomerism in organic chemistry.

- State the concept of homologous compounds and homologous series.

- Write structural formulas of some simple organic compounds (complete structural formula, simplified structural formula).

- State homologous compounds, isomers based on specific structural formulas of organic compounds.

Methods of separating and purifying organic compounds:

- Present principles and methods for separating and purifying organic compounds: distillation, extraction, crystallization, and a brief overview of column chromatography.

- Conduct experiments on common distillation, extraction.

- Apply methods: common distillation, extraction, crystallization to separate and purify some organic compounds in real life.

Organic compounds and organic chemistry:

- State the concept of organic compounds and organic chemistry; common characteristics of organic compounds.

- Classify organic compounds (hydrocarbons and derivatives).

- State the concept of functional groups and some basic types of functional groups.

- Use infrared (IR) spectra charts to determine some basic functional groups.

Thus, students in Vietnam will study and learn about the molecular formula in the 11th-grade Chemistry curriculum.

What are the 2 academic topics in the 11th-grade Chemistry curriculum in Vietnam?

Under Section 5 of the General education program in Chemistry issued with Circular 32/2018/TT-BGDDT, the requirements for 11th-grade Chemistry are as follows:

* Academic topics

- Objectives

In addition to core educational content, in each school year, students with a propensity for natural sciences are selected to study certain topics. The objectives of these topics are:

+ Expand and deepen knowledge to meet the in-depth differentiation requirements at the high school level.

+ Enhance practicing skills, and real-life experiential activities as a basis to help students better understand technical and technological processes related to chemistry.

+ Help students understand more deeply the role of chemistry in real life, and occupations related to chemistry, providing a basis for career orientation as well as equipping them with the capability to solve problems related to chemistry and continue lifelong self-learning in chemistry.

- Content of academic topics

Topic 11.2. Experience, practice organic chemistry

Topic 11.1. Fertilizers

Thus, according to the above provision, the 2 topics 11th-grade students will study in the Chemistry curriculum are Experience, practice organic chemistry and Fertilizers.