Lesson 10 Thermal Decomposition Chemistry Key Stage 3

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Lesson 10 - Thermal Decomposition Chemistry- Key Stage 3 Energetics 1

Lesson 10 - Thermal Decomposition Chemistry- Key Stage 3 Energetics 1

During endothermic reactions. . . A B The temperature of the surroundings increases surroundings

During endothermic reactions. . . A B The temperature of the surroundings increases surroundings decreases C D The particles decrease in The particle temperature increases

During endothermic reactions. . . A Bonds are broken B Nothing happens to the

During endothermic reactions. . . A Bonds are broken B Nothing happens to the bonds C New bonds are made D Bonds are broken and made

Thermal Decomposition of Ammonium Dichromate Reactant (NH 4)2 Cr 2 O 7 (s) (l)

Thermal Decomposition of Ammonium Dichromate Reactant (NH 4)2 Cr 2 O 7 (s) (l) Products Cr 2 O 3 (s) + N 2 (g) + 4 H 2 O

Naming products of thermal decomposition Copper → Copper + Carbon dioxide carbonate oxide Cu.

Naming products of thermal decomposition Copper → Copper + Carbon dioxide carbonate oxide Cu. CO 3 1. __________ → Cu. O + CO 2 → Magnesium + Carbon dioxide 1. Zinc → Zinc carbonate ____ + ___________ Symbols Mg= Magnesium Zn= Zinc O= Oxygen C= Carbon

Conservation of mass Mass is never created or destroyed H O O H +

Conservation of mass Mass is never created or destroyed H O O H + → H H ? g + 22 g → 43 g Mass of reactants = mass of products

Complete the task Describe and explain in terms of conservation of mass thermal decomposition

Complete the task Describe and explain in terms of conservation of mass thermal decomposition of calcium carbonate Calcium → calcium + carbonate oxide dioxide O C O 10 g O O O Ca ? g C Ca → O 7 g +

Answers 8

Answers 8

During endothermic reactions. . . A B The temperature of the surroundings increases surroundings

During endothermic reactions. . . A B The temperature of the surroundings increases surroundings decreases C D The particles decrease in The particle temperature increases

During endothermic reactions. . . A Bonds are broken B Nothing happens to the

During endothermic reactions. . . A Bonds are broken B Nothing happens to the bonds C New bonds are made D Bonds are broken and made

Thermal Decomposition of Ammonium Dichromate Reactant (NH 4)2 Cr 2 O 7 (s) (l)

Thermal Decomposition of Ammonium Dichromate Reactant (NH 4)2 Cr 2 O 7 (s) (l) Products Cr 2 O 3 (s) + N 2 (g) + 4 H 2 O N=2 H=8 Cr=2 O=7

Naming products of thermal decomposition 1. Magnesium → Magnesium + carbon dioxide carbonate oxide

Naming products of thermal decomposition 1. Magnesium → Magnesium + carbon dioxide carbonate oxide Mg. CO 3 1. Zinc → → carbonate Zn. CO 3 Mg. O Zinc + + carbon oxide → Zn. O CO 2 dioxide + CO 2

Conservation of mass Mass is never created or destroyed H O O H +

Conservation of mass Mass is never created or destroyed H O O H + → H H 21 g + 22 g → 43 g Mass of reactants = mass of products

Explain in terms of conservation of mass thermal decomposition of calcium carbonate ● When

Explain in terms of conservation of mass thermal decomposition of calcium carbonate ● When calcium carbonate decomposes, it breaks down and produces calcium oxide and carbon dioxide. ● The mass of product = the mass of reactants. ● mass of Ca. CO 3 = 10 g, mass of Ca. O+CO 2= 10 g. ● 10 g-7 g (Ca. O)= 3 g (CO 2)