What are the 5+ exercise types for balancing Chemical equations and solving methods? What is the duration for 8th-grade Natural Science in Vietnam?
What are the 5+ exercise types for balancing Chemical equations and solving methods?
Type 1: Complete and Balance Chemical Equations
| Exercises: MgCl2 + KOH → Mg(OH)2 + KCl Cu(OH)2 + HCl → CuCl2 + H2O Cu(OH)2 + H2SO4 → CuSO4 + H2O FeO + HCl → FeCl2 + H2O Fe2O3 + H2SO4 → Fe2(SO4)3 + H2O Cu(NO3)2 + NaOH → Cu(OH)2 + NaNO3 P + O2 → P2O5 N2 + O2 → NO NO + O2 → NO2 NO2 + O2 + H2O → HNO3 Na2O + H2O → NaOH Ca(OH)2 + Na2CO3 → CaCO3 + NaOH Fe2O3 + H2 → Fe + H2O Mg(OH)2 + HCl → MgCl2 + H2O FeI3 → FeI2 + I2 AgNO3 + K3PO4 → Ag3PO4 + KNO3 SO2 + Ba(OH)2 → BaSO3 + H2O Ag + Cl2 → AgCl FeS + HCl → FeCl2 + H2S Pb(OH)2 + HNO3 → Pb(NO3)2 + H2O Solutions: MgCl2 + 2KOH → Mg(OH)2 + 2KCl Cu(OH)2 + 2HCl → CuCl2 + 2H2O Cu(OH)2 + H2SO4 → CuSO4 + 2H2O FeO + 2HCl → FeCl2 + H2O Fe2O3 + 3H2SO4 → Fe2(SO4)3 + 3H2O Cu(NO3)2 + 2NaOH → Cu(OH)2 + 2NaNO3 4P + 5O2 → 2P2O5 N2 + O2 → 2NO 2NO + O2 → 2NO2 4NO2 + O2 + 2H2O → 4HNO3 Na2O + H2O → 2NaOH Ca(OH)2 + Na2CO3 → CaCO3 + 2NaOH Fe2O3 + 3H2 → 2Fe + 3H2O Mg(OH)2 + 2HCl → MgCl2 + 2H2O 2FeI3 → 2FeI2 + I2 3AgNO3 + K3PO4 → Ag3PO4 + 3KNO3 SO2 + Ba(OH)2 → BaSO3 + H2O 2Ag + Cl2 → 2AgCl FeS + 2HCl → FeCl2 + H2S Pb(OH)2 + 2HNO3 → Pb(NO3)2 + 2H2O |
Type 2: Identify Appropriate Coefficients to Balance Equations
| Exercises: Al2O3 + ? → ?AlCl3 + ?H2O H3PO4 + ?KOH → K3PO4 + ? ?NaOH + CO2 → Na2CO3 + ? Mg + ?HCl → ? + ?H2 ? H2 + O2 → ? P2O5 + ? → ?H3PO4 CaO + ?HCl → CaCl2 + H2O CuSO4 + BaCl2 → BaSO4 + ? Solutions: Al2O3 + 6HCl → 2AlCl3 + 3H2O H3PO4 + 3KOH → K3PO4 + 3H2O 2NaOH + CO2 → Na2CO3 + H2O Mg + 2HCl → MgCl2 + H2 2H2 + O2 → 2H2O P2O5 + 3H2O → 2H3PO4 CaO + 2HCl → CaCl2 + H2O CuSO4 + BaCl2 → BaSO4 + CuCl2 |
Type 3: Atomic Schemas Established and Mole Ratio of Substances Post-Reaction
| Exercises: a) Na + O2 → Na2O b) P2O5 + H2O → H3PO4 c) HgO → Hg + O2 d) Fe(OH)3 → Fe2O3 + H2O Solutions: a) 4Na + O2 → 2Na2O Ratio: Na atoms : O2 molecules : Na2O molecules = 4 : 1 : 2 b) P2O5 + 3H2O → 2H3PO4 Ratio: P2O5 molecules : H2O molecules : H3PO4 molecules = 1 : 3 : 2 c) 2HgO → 2Hg + O2 Ratio: HgO molecules : Hg atoms : O2 molecules = 2 : 2 : 1 d) 2Fe(OH)3 → Fe2O3 + 3H2O Ratio: Fe(OH)3 molecules : Fe2O3 molecules : H2O molecules = 2 : 1 : 3 |
Type 4: Balancing Equations with Organic Compounds
| Exercises: CnH2n + O2 → CO2 + H2O CnH2n + 2 + O2 → CO2 + H2O CnH2n - 2 + O2 → CO2 + H2O CnH2n - 6 + O2 → CO2 + H2O CnH2n + 2O + O2 → CO2 + H2O Solutions: CnH2n + O2 → nCO2 + nH2O CnH2n + 2 + O2 → nCO2 + (n+1)H2O CnH2n - 2 + O2 → nCO2 + (n-1)H2O CnH2n - 6 + O2 → nCO2 + (n-3)H2O CnH2n + 2O + O2 → nCO2 + (n+1)H2O |
Type 5: Chemical Equations with Variables
| Exercises: FexOy + H2 → Fe + H2O FexOy + HCl → FeCl2y/x + H2O FexOy + H2SO4 → Fe2(SO4)2y/x + H2O M + H2SO4 → M2(SO4)n + SO2 + H2O M + HNO3 → M(NO3)n + NO + H2O FexOy + H2SO4 → Fe2(SO4)2y/x + SO2 + H2O Solutions: FexOy + yH2 → xFe + yH2O FexOy + 2yHCl → xFeCl2y/x + yH2O 2FexOy + 2yH2SO4 → xFe2(SO4)2y/x + 2yH2O 2M + 2nH2SO4 → M2(SO4)n + nSO2 + 2nH2O M + 2nHNO3 → M(NO3)n + 2nNO + H2O FexOy + yH2SO4 → xFe2(SO4)2y/x + ySO2 + yH2O |
Note: The content is for reference only!
What are the 5+ exercise types for balancing Chemical equations and solving methods? What is the duration for 8th-grade Natural Science in Vietnam? (Image from the Internet)
What is the duration for 8th-grade Natural Science in Vietnam?
In the General Education Program for Natural Science issued alongside Circular 32/2018/TT-BGDDT:
The duration by each grade is 140 lessons per academic year, taught over 35 weeks. The estimated percentage of lessons allocated for each topic is presented in the table below:
| Content | Grade 6 | Grade 7 | Grade 8 | Grade 9 |
| Introduction | 5% | 4% | 2% | 2% |
| Substances and Chemical Changes | 15% | 20% | 29% | 31% |
| States of Matter | 3% | |||
| Oxygen and Air | 2% | |||
| Common Materials, Fuels, Raw Materials, Food | 6% | |||
| Solutions; Separating Substances from Mixtures | 4% | |||
| Atoms. Chemical Elements | 6% | |||
| Molecules | 9% | |||
| Brief Overview of the Periodic Table of Chemical Elements | 5% | |||
| Chemical Reactions | 12% | |||
| Reaction Rates and Catalysts | 3% | |||
| Acid - Base - pH - Oxide - Salt; Chemical Fertilizers | 14% | |||
| Metals | 8% | |||
| Basic Differences between Nonmetals and Metals | 4% | |||
| Introduction to Organic Substances Hydrocarbons and Fuel Sources |
7% | |||
| Ethylic Alcohol, Acetic Acid; Lipids - Carbohydrates - Proteins Polymers | 12% | |||
| Living Organisms | 38% | 38% | 29% | 25% |
| Cells - The Fundamental Unit of Life | 11% | |||
| Biodiversity | 27% | |||
| Metabolism and Energy Transformation in Organisms | 23% | |||
| Response in Organisms | 3% | |||
| Growth and Development in Organisms | 5% | |||
| Reproduction in Organisms; Organisms as a Unified Body | 7% | |||
| Human Body Biology | 20% | |||
| Environment; Ecosystems | 9% | |||
| Genetic Phenomena | 19% | |||
| Evolution | 6% | |||
| Energy and Transformation | 25% | 28% | 28% | 28% |
| Measurements | 7% | |||
| Force | 11% | 8% | 6% | |
| Density and Pressure | 8% | |||
| Energy and Life | 7% | 6% | 7% | |
| Sound | 7% | |||
| Light | 6% | 9% | ||
| Electricity | 8% | 7% | ||
| Magnetism | 7% | 5% | ||
| Earth and the Sky | 7% | 0% | 2% | 4% |
| Visible Motion of the Sun, Moon; Solar System; Milky Way | 7% | |||
| Biosphere and Biomes on Earth | 2% | |||
| Resource Extraction from Earth's Crust; Brief "Chemistry About Earth's Crust" | 4% | |||
| Periodic Assessment | 10% | 10% | 10% | 10% |
Thus, the duration of 8th-grade Natural Science in Vietnam is 140 lessons over 35 weeks.
What do the equipment, specimens, and chemicals used for practical lessons under the 8th-grade Natural Science curriculum in Vietnam include?
Under the General Education Program for Natural Science issued in association with Circular 32/2018/TT-BGDDT, the equipment, specimens, and chemicals used for practical lessons under the 8th-grade Natural Science curriculum in Vietnam include:
- Length, area, volume, mass, temperature, time measuring tools; measurement car with integrated position sensor, force sensor for motion and friction force studies;
- Dynamometers, measuring tapes, permanent magnets, spring scales; audio frequency generators, tuning forks, oscilloscopes; tools for creating and displaying light beams, illuminating areas, mixing light colors; plane mirrors, prisms; tools for magnetic field studies, student compasses; permanent magnets, electromagnets;
- Devices for examining material density and surface pressure; simple apparatus for creating levers; tools for generating and redistributing electric charges (Van de Graaff generator, soft silk, plastic comb, etc.); electric energy measurement kit (joulemeter);
- Kits for studying light reflection; kits for studying light refraction; digital scales; portable pH meters; glassware such as: test tubes, flasks, jars, beakers, funnels, bowls, pipettes, etc.; chemicals: essential chemicals needed for demonstration and practical experiments.
- Specimens of fertilizers; models, sets for assembling hollow, solid molecules of alkanes, ethylic alcohol, acetic acid.
- Microscopy specimens of cells and cell organelles; kits for preparing dried plant specimens, soaking animal specimens; kits for exploring wild organisms.
- Practical kits for applying bandages to fractures, blood pressure monitors, bandaging tools for bleeding injuries. c) Subject room
- Sufficient room space to store equipment, specimens, and tables, chairs for students to conduct practical lessons, water taps, sinks, fire safety equipment.
- Fixed equipment: writing board, specimen cupboard, consumables (chemicals, glassware, experiment trays), chemical and laboratory apparatus racks, chart hanging racks, stone-covered practice tables, refrigerators, drying cabinets, dehumidifiers, ventilation fans, protective equipment, tools used according to practical lessons.
- Electronic and optical, audiovisual equipment: microscopes, magnifying glasses, binoculars, computers, projectors, screens, TVs, etc.
