Thermal decomposition of carbonates

1. Thermal decomposition of carbonates Key words; balanced chemical equation

2. Learning Objectives: By the end of the lesson I can: • Most metal carbonates will undergo thermal decomposition. Metal carbonates all decompose on heating in a similarly. • Atoms are rearranged in a chemical reaction. Atoms and symbols are used to represent and explain what is happening to the substances in chemical reactions. • Conservation of mass occurs in a chemical reaction. No atoms are lost or made during a chemical reaction so the mass of the products equals the mass of the reactants and we can write balanced equations showing the atoms involved.

3. What are we learning about today? starter Thermal Decomposition HINT: acdeehiimmnotolports Using heat to break down a substance

4. Recap Interpersonal: THINK FOR 30SECS What do you expect to be produced when potassium carbonate is decomposed? Intrapersonal:CHAT with your partner THERMAL DECOMPOSITION occurs when heat is used to breakdown substances. When LIMESTONE decomposes then CARBON DIOXIDE and CALCIUM OXIDE is produced. LIMEWATER TURNS MILKY when a person blows through a straw into the solution. This is the lab test for CARBON DIOXIDE. Write a GENERAL equation for the thermal decomposition of metal oxides

5. OVERVIEW: You and your partner will study a metal carbonate by Describing its appearance Plan the thermal decomposition investigation Complete the thermal decomposition investigation Explain your findings to another table group (red-yellow, green-blue) Task: Use your knowledge

6. Aim To plan an experiment to compare how different metal carbonates decompose when heated. Equipment 2 x Test tubes and Delivery tubing Retort stand and clamp Bunsen burner and heat proof mat Spatula, Metal carbonate and Limewater Method (Your plan should include the following: A diagram of the apparatus. A step-by-step account of how you would do the experiment. A description of the following: How you are going to tell when the carbonates have decomposed.? - How you will compare how quickly they decompose? - How can you time exactly when the limewater goes milky? - Is it possible to make this consistent? – controlling variables - How can you make this experiment safe?) The decomposition of metal carbonates

7. Results Draw out a table using the headings below and write down the observations for each metal carbonate Name of carbonate Observations Conclusions What patterns can you detect from your results? Was your test fair? Were your results accurate? Reliable? The decomposition of metal carbonates

8. Join another pair from another table and spend 10 mins each to teach what has happened in the experiment you have just completed. Peer Learning plenary

9. Learning Objectives: By the end of the lesson I can: • Most metal carbonates will undergo thermal decomposition. Metal carbonates all decompose on heating in a similarly. • Atoms are rearranged in a chemical reaction. Atoms and symbols are used to represent and explain what is happening to the substances in chemical reactions. • Conservation of mass occurs in a chemical reaction. No atoms are lost or made during a chemical reaction so the mass of the products equals the mass of the reactants and we can write balanced equations showing the atoms involved.

10. Complete the following equations; Chemical Reactions starter Calcium Carbonate magnesium oxide + carbon dioxide CuO + CO2 ZnCO3

11. Use the MASS NUMBER of each element to write balanced chemical equations For each of the chemical reactions above;

12. Thermal decomposition of magnesium carbonate Calcium added to hydrochloric acid Zinc metal added to sulphuric acid Calcium oxide is added to water to form a single compound Thermal decomposition of calcium carbonate Zinc metal added to hydrochloric acid Calcium is added to water Magnesium metal is burnt Hydrogen gas is added to chlorine gas Calcium is added to oxygen gas Magnesium metal is added to hydrochloric acid Practice these equations in FULL – you choose the level of difficulty;

13. Bonding Key words; ionic, covalent, bonding

14. Learning Objectives: By the end of the lesson I can: • •Compounds can be formed by ionic and covalent bonding. • •Ionic bonding involves the giving or taking of electrons. • •Covalent bonding involves the sharing of electrons. • All bonding takes place to stabilise elements.

15. MASSNUMBER PROTONNUMBER (ATOMIC) How many neutrons are there? • The mass number is the total number of protons and neutrons in the nucleus • The proton (atomic) number is the number of protons in the nucleus.

16. What about electrons? • The mass number is the total number of protons and neutrons in the nucleus • The proton (atomic) number is the number of protons in the nucleus. The number of electrons equals the number of protons

17. Electron Configuration tells us how the electrons are arranged around the nucleus in energy levels (shells). • The first energy level (shell) can contain a maximum of 2 electrons • The next energy levels (shell) can contain a maximum of 8 electrons • 2,8,8,8 etc…

18. Have a go at drawing out carbon in a dot and cross diagram… Mass number > Proton number > What is the electron configuration?

19. RULES Proton number = Protons in the nucleus Mass number = Protons + Neutrons in the nucleus Number of Protons = Number of Electrons Electron configuration = 2,8,8,8

20. Draw dot and cross diagrams for: • Sodium • Potassium • Fluorine • Chlorine

21. Plenary How many protons and neutrons in the nucleus? How many electrons? What is the electron configuration? How many electrons in the outer shell? 23 Na 11

22. Ionic bonding occurs between metal elements and non-metal elements • The outer electrons are not shared but they are donated or gained. (Given away or received) Why do elements want to share, donate or gain electrons?

23. Na Cl Would it be easier to lose 1 or gain 7 electrons to have a full outer shell? Task Two

24. Cl - + Na What compound is formed?

25. S Mg What do you think will happen here?

26. 2- 2+ S Mg What is the name of this compound?

27. Have a go!!!! • Draw out the following simple Ionic compounds: • Potassium chloride – KCl • Lithium fluoride -LiF • Sodium iodide – NaI Start by drawing a dot and cross diagram.

28. Can you name the compounds? • MgO • NaCl • CO • FeS • FeSO4 • LiOH Which are ionic compounds? Magnesium Oxide Sodium Chloride Carbon Monoxide Iron (II) Sulphide Iron (II) Sulphate Lithium Hydroxide

29. H H H H The covalent bond When non-metal atoms react together, they need to gain electrons to fill their outer shell and become stable. incomplete outer shells They can only do this if they share electrons with each other. The atoms share electrons so there is a strong force that joins the atoms together. both atoms have a full outer shell This is called a covalent bond.

30. H H Task Two 1) Draw dot and cross diagrams for the following simple covalent compounds a) Chlorine gas (Cl2) b) Methane (CH4) c) Ammonia (NH3) Have a go!

31. H H H C Cl Cl Cl O H H H

32. Learning Objectives: By the end of the lesson I can: • •Compounds can be formed by ionic and covalent bonding. • •Ionic bonding involves the giving or taking of electrons. • •Covalent bonding involves the sharing of electrons. • All bonding takes place to stabilise elements.