测试版本平台正在积极开发中；可能存在 Bug、功能缺失和数据丢失风险。感谢你的支持！

Thermal decomposition

边玩边学

回答这些题目来赚取能量，然后钓鱼探索。无需账号。

给老师： 面向 Thermal decomposition（KS3 Science，Chemistry）的即用型课程幻灯片, 复习笔记, 图示——用在你的课堂上，或将该知识点作为学生可实时游玩的互动课堂活动来运行。

课程笔记

What is Thermal Decomposition?

  • Thermal decomposition is a chemical reaction where a compound is heated and breaks down into smaller, simpler products.
  • It requires heat energy to break the chemical bonds in the compound.

Example: Copper Carbonate

  • Heating copper carbonate (green) produces copper oxide (black) and carbon dioxide gas.
  • Word equation: copper carbonate → copper oxide + carbon dioxide.
  • Symbol equation: CuCO₃ → CuO + CO₂.
  • The colour change from green to black is evidence of a chemical reaction.
  • The release of carbon dioxide gas is another sign of reaction.

General Rule for Metal Carbonates

  • When heated, a metal carbonate generally decomposes into a metal oxide and carbon dioxide.
  • Example: magnesium carbonate → magnesium oxide + carbon dioxide (MgCO₃ → MgO + CO₂).
  • Example: calcium carbonate → calcium oxide + carbon dioxide (CaCO₃ → CaO + CO₂).

Testing for Carbon Dioxide

  • Carbon dioxide gas turns limewater (calcium hydroxide solution) milky/cloudy white.
  • This is a positive test for carbon dioxide.

Example: Hydrogen Peroxide

  • Hydrogen peroxide decomposes into water and oxygen gas when heated.
  • Word equation: hydrogen peroxide → water + oxygen.
  • Balanced symbol equation: 2H₂O₂ → 2H₂O + O₂.

Testing for Oxygen

  • Oxygen gas will relight a glowing splint.
  • This is a positive test for oxygen.

Balancing Equations

  • Example: Silver oxide decomposes: 2Ag₂O → 4Ag + O₂ (balanced).
  • Always ensure the number of atoms of each element is equal on both sides.

Particle arrangement in solids, liquids, and gases. Thermal decomposition involves breaking bonds, often producing gases.

Particle arrangementSolidLiquidGas

幻灯片

Sign up free to view the lesson slides

Step through every slide for this topic — plus flashcards and revision notes — with a free account.

注册——免费登录

练习题

免费预览——56 题中的 8 题。注册即可查看全部。

  1. 1.What is thermal decomposition?

    Easy
    • AA reaction where a compound is heated and breaks down into simpler products
    • BA reaction where two elements combine to form a compound
    • CA reaction where a substance burns in oxygen
    • DA reaction where a compound is broken down by electricity

  2. 2.When copper carbonate undergoes thermal decomposition, what are the products?

    Easy
    • ACopper oxide and carbon dioxide
    • BCopper and carbon dioxide
    • CCopper oxide and oxygen
    • DCopper and oxygen

  3. 3.What colour change occurs when copper carbonate is heated?

    Easy
    • AFrom green to black
    • BFrom black to green
    • CFrom green to white
    • DFrom white to black

  4. 4.Which test is used to confirm that a gas is carbon dioxide?

    Easy
    • ABubble the gas through limewater; it turns milky
    • BHold a glowing splint near it; it relights
    • CHold a lighted splint near it; it pops
    • DCollect the gas in a test tube and smell it

  5. 5.Balance the equation: ___ Ag2O → ___ Ag + O2

    Medium
    • A2 Ag2O → 4 Ag + O2
    • BAg2O → 2 Ag + O2
    • C2 Ag2O → 2 Ag + O2
    • D3 Ag2O → 6 Ag + O2

  6. 6.Which of the following is a sign that a chemical reaction has occurred when heating copper carbonate?

    Easy
    • AA colour change and gas release
    • BOnly a colour change
    • COnly gas release
    • DNo change is observed

  7. 7.What is the balanced chemical equation for the thermal decomposition of hydrogen peroxide?

    Medium
    • A2 H2O2 → 2 H2O + O2
    • BH2O2 → H2O + O2
    • C2 H2O2 → H2O + 2 O2
    • DH2O2 → 2 H2O + O2

  8. 8.What is the test for oxygen gas?

    Easy
    • AIt relights a glowing splint
    • BIt turns limewater milky
    • CIt burns with a squeaky pop
    • DIt bleaches damp litmus paper

Unlock all 56 questions, flashcards & more

创建免费账号，即可查看该知识点的每一道题、幻灯片、闪卡和复习笔记。

注册——免费登录

历年真题

该知识点的历年真题练习即将推出。
即将推出