ما هي معادلة الأسترة وكيف يتكون الإستر؟ What is the esterification reaction equation?

تفاعل الأسترة هو تفاعل انعكاسي بين حمض كربوكسيلي وكحول في وجود حمض الكبريتيك المركز كعامل حفاز لنزع الماء: R-COOH + R2-OH ⇌ R-COO-R2 + H₂O، ونواتجه إستر وماء. [الصيغة الرمزية الموزونة: R-COOH + R2-OH ⇌ (conc. H₂SO₄) R-COO-R2 + H₂O]

2dInorganic Chemistry

Reactivity series — Edexcel Linear - OL (Chemistry) Revision Notes & Topical Questions

10 min read 12 parts Lesson 4 of 23 1 quiz

📚 Edexcel Linear - OL (Chemistry) Hub / Topical Revision

Curriculum Equation Key معادلة تفاعل تكوين الإستر (الأسترة) - Esterification Reaction EquationFast Exam Solution

R-COOH + R2-OH ⇌ (conc. H₂SO₄) R-COO-R2 + H₂O

Word Equation & Conditions: حمض كربوكسيلي + كحول (في وجود حمض الكبريتيك المركز كعامل حفاز ونازع للماء) ⇌ إستر + ماء

Location & Specifications: الكيمياء العضوية للثانوية العامة والتحصيلي و Edexcel Chemistry.

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Lesson summary

Reactivity series Edexcel O Level Linear Chemistry notes: understand how metals can be arranged in a reactivity series based on their reactions with: - water - dilute hydrochloric or sulfuric acid.Gold is found as the pure metal because it is so unreactive.Rusting needs both oxyg…

Reactivity series Edexcel O Level Linear Chemistry: what to do next
Metal oxide
Metal hydroxide
Displacement
Give / State / Name
Evaluate / Assess

Part 1 of 6Key ideas

Key ideas

Gold is found as the pure metal because it is so unreactive.

Rusting needs both oxygen and water.

Painting, oiling and galvanising prevent rust.

Part 2 of 6Syllabus points

understand how metals can be arranged in a reactivity series based on their reactions with: - water - dilute hydrochloric or sulfuric acid.

understand how metals can be arranged in a reactivity series based on their displacement reactions between: - metals and metal oxides - metals and aqueous solutions of metal salts.

know the order of reactivity of these metals

potassium, sodium
lithium
calcium
magnesium
aluminium, zinc, iron, copper, silver, gold

know the conditions under which iron rusts

understand how the rusting of iron may be prevented by: - barrier methods - galvanising - sacrificial protection.

understand the terms: - oxidation - reduction - redox - oxidising agent - reducing agent in terms of gain or loss of oxygen and loss or gain of electrons.

practical: investigate reactions between dilute hydrochloric and sulfuric acids and metals (e.g. magnesium, zinc and iron)

Part 3 of 6Process & sequence

Word equations

Metal + oxygen → metal oxide

Metal + water → metal hydroxide + hydrogen

Metal + steam → metal oxide + hydrogen

Part 4 of 6Summary

Summary

The most reactive common metal is potassium.

Metal + water → metal hydroxide + hydrogen.

Part 5 of 6Keep going

Reactivity series Edexcel O Level Linear Chemistry: what to do next

These Reactivity series Edexcel O Level Linear Chemistry notes covered the key ideas, worked examples and exam technique for this topic. Check your Reactivity series Edexcel O Level Linear Chemistry understanding with the practice questions below, then reread any Reactivity series Edexcel O Level Linear Chemistry point you were unsure about before moving on.

Practice: Reactivity series Edexcel O Level Linear Chemistry practice questions

Previous lesson: 2c Gases in the atmosphere — Notes

Next lesson: 2f Acids, alkalis and titrations — Notes

Course: Edexcel Linear – OL (chemistry) — all units

Official syllabus: Pearson Edexcel International GCSEs

Part 6 of 6Compare: Compare

Metals in the reactivity series
Metal	With oxygen	With cold water	With steam	Products with water	Reactivity
Potassium	Burns vigorously	Very violent, lilac flame	—	Potassium hydroxide + hydrogen	Most
Sodium	Burns brightly	Violent, fizzes around	—	Sodium hydroxide + hydrogen	Very high
Calcium	Burns	Fizzes steadily	—	Calcium hydroxide + hydrogen	High
Magnesium	Burns with white light	Very slow	Reacts	Magnesium oxide + hydrogen (steam)	Medium
Zinc / iron	Slow / rusts	No reaction	Reacts slowly	Oxide + hydrogen	Low
Copper	Forms black oxide when heated	No reaction	No reaction	—	Very low
Gold	No reaction	No reaction	No reaction	—	Least

Key terms

Command terms

Give / State / Name

Recall a fact; one idea per mark.

Define

Give the exact meaning using the specification keywords.

Describe

Give an account of what happens / the pattern in data, quoting values; no reasons needed.

Explain

Give reasons with linked statements (cause → effect). Each linked step is usually a separate marking point.

Suggest

Use knowledge in a new context; more than one answer may be accepted.

Compare

Similarities and differences; each point must refer to both items.

Calculate

Show working; include units; check significant figures. Method marks are given even if the final answer is wrong.

Discuss

Explore the issue from different angles and link the points.

Evaluate / Assess

Weigh strengths and weaknesses and reach a supported judgement.

Deduce

Draw a conclusion from the information given.

Justify

Support a statement/choice with evidence.

Exam technique

Keywords the mark scheme looks for in this lesson

Reactivity series · Oxidation · Metal oxide · Metal hydroxide · Hydrogen · Corrosion · Rusting · Displacement

Learn each definition in the Key words tab exactly; a missing keyword in a definition usually loses the mark.

How to get full marks (examiner guidance)

Use specification keywords exactly (e.g. electronegativity, nucleophile, dynamic equilibrium, activation energy).

Link ideas

Link ideas for “explain” each marking point is usually a cause → consequence step; unlinked facts often score nothing.

Use the information in the question

“discuss/evaluate” answers must use the data provided and match the number of marks.

Convert units carefully (mg → g, cm³ → dm³) and show working for calculations.

Avoid vague words

“it”, “stuff”, “things”, “goes up”, “energy is made”. Name the substance and the process.

Do not extrapolate a graph line beyond the data or to zero unless asked.

Six-mark extended responses are marked on content AND a logical, linked line of reasoning.

Last updated: 11 October 2026