1. Chemical Synthesis Lesson 2

2. Learning objective: To explain the reactions involving acids. Must: Describe the pH scale. Grade D Must: Describe what happens during a neutralisation reaction. Grade C Should: Predict the name of products formed during acid reactions. Grade B Could: Write balanced symbol equations for the acid reactions. Grade A Keywords: pH scale, salt, acid, word equation and balanced equation.

3. Let’s make a rainbow. Key skill used. That you can read and understand texts and take the appropriate action. As a team worker you can collaborate with others to work towards common goals.

4. pH scale. The pH scale tells us how acidic or alkaline a solution is. It is used to measure and help control the pH in a range of industries. industries.

5. 1.Indicators can be used to find out whether a solution is acid, alkaline or neutral 2.Universal Indicator can be used to find the pH of a solution Acid – red, pH less than 7 Neutral – green, pH = 7 Alkali – blue, pH greater than 7 pH scale

8. Important acids. Hydrochloric acid – HCl (aq) Nitric acid– HNO 3(aq) Sulfuric acid – H 2 SO 4(aq) Make sure you learn and remember them! What does the (aq) mean?

9. Acidic compounds in different states. Acids that are solids – citric and tartaric. Acids that are liquids – nitric, sulfuric and ethanoic. Acids that are gases – hydrogen chloride.

10. Formula of some alkalis. Sodium hydroxide – NaOH Potassium hydroxide – KOH Magnesium hydroxide – Mg(OH) 2 Learn and remember these!

11. What is an acid? All acids contain hydrogen atoms. When acids dissolve in water they produce hydrogen ions, H +. HCl(g)  H + (aq) + Cl - (aq) That is why acids only behave like acids when they are dissolved in water.

12. What about alkalis? The same can be applied to alkalis. This time it is the presence of the OH - ion that makes a substance an alkali. Strong alkalis like NaOH sodium hydroxide split up completely. NaOH(aq)  Na + (aq) + OH - (aq)

13. What happens to the ions during neutralisation.

14. Ionic equations The reaction between acids and alkalis can be represented by the following equation: Acid and alkali H + (aq) + OH - (aq)  H 2 O (l) Note that water is produced.

15. Learning objective: To explain the reactions involving acids. Must: Describe the pH scale. Must: Describe what happens during a neutralisation reaction. Should: Predict the name of products formed during acid reactions. Could: Write balanced symbol equations for the acid reactions. Keywords: pH scale, salt, acid, word equation and balanced equation.

16. Neutralisation – Hydrochloric acid Neutralisation

17. Neutralisation – Sulphuric acid Neutralisation

18. Neutralisation – Nitric acid Neutralisation

19. Discover - Monitoring Neutralisation. Follow the instructions for AC6.13. Add 5 cm 3 of HCl up to 35cm 3 and then 1cm 3 up to 45cm 3 Record your results and plot the graph. Make sure you wear goggles. Key skills Read and understand texts and take appropriate action. Use appropriate mathematical procedures. Examine patterns and relationships. Team worker – collaborate with others to work towards common goals.

20. Strong acid/base titration. This is the shape of the curve when a strong acid is reacted with a strong base. What do you notice about the shape?

21. Testing understanding. Click here for more examples of neutralisation reactions.Click here Click here for more information and tests about acids and alkalis.Click here

22. Learning objective: To explain the reactions involving acids. Must: Describe the pH scale. Must: Describe what happens during a neutralisation reaction. Should: Predict the name of products formed during acid reactions. Could: Write balanced symbol equations for the acid reactions. Keywords: pH scale, salt, acid, word equation and balanced equation.

23. Discover - Investigating acids. Follow the instructions for AC6.3. Record your results and write word equations for each reaction. Make sure you are wearing goggles. Key skills. Read and understand texts and take appropriate action. Team worker – collaborate with others to work towards common goals.

24. 1.Acids react with alkaline solutions to form a salt and water Hydrochloric acid produces chlorides Nitric acid produces nitrates Sulphuric acid produces sulphates Naming Salts Neutralisation

25. Reactions of metals with acids Copy and complete the following reactions: 1)Calcium + hydrochloric acid 2)Zinc + hydrochloric acid 3)Iron + hydrochloric acid 4)Lithium + sulphuric acid METAL + ACID SALT + HYDROGEN e.g. magnesium + hydrochloric acid magnesium chloride + hydrogen Mg H Cl Mg Cl H H H

26. Reactions of metal oxides with acid A metal oxide is a compound containing a metal and oxide. They are sometimes called BASES. For example: Mg O Na O O Al O O Magnesium oxide Sodium oxide Aluminium oxide METAL OXIDE + ACID SALT + WATER Copy and complete the following reactions: 1)Magnesium oxide + hydrochloric acid 2)Calcium oxide + hydrochloric acid 3)Sodium oxide + sulphuric acid Mg O H Cl Mg Cl H H O H

27. Acid alkali reactions A neutralisation reaction occurs when an acid reacts with an alkali. An alkali is a metal oxide or metal hydroxide dissolved in water. ACID + ALKALI SALT + WATER Na Cl H H O H Na O H Copy and complete the following reactions: 1)Sodium hydroxide + hydrochloric acid 2)Calcium hydroxide + hydrochloric acid 3)Sodium hydroxide + sulphuric acid 4)Magnesium hydroxide + sulphuric acid

28. Reactions of metals carbonates with acid A metal carbonate is a compound containing a metal, carbon and oxygen. METAL CARBONATE + ACID SALT + CARBON DIOXIDE + WATER Copy and complete the following reactions: 1)Magnesium carbonate + hydrochloric acid 2)Calcium carbonate + hydrochloric acid 3)Sodium carbonate + sulphuric acid Mg H Cl Mg Cl H H H C O O O O O O C

29. Testing understanding. Click here for more word and symbol equations for reactions involving acids. Click here Click here for revision notes and test on reactions involving acids. Click here