7. What are Acids? Acids are common Some are dangerous and can burn your skin Some are safe to eat and drink Stomach acid helps digest food explosion
8. Acids Definition A group of compounds which behave similarly All have low pH Turn Litmus paper RED All donate H+ ions in aqueous solution Examples Hydrochloric HCl Sulfuric H2SO4 Nitric HNO3
9. Acids A dilute acid has lots of water and a small amount of acid A concentrated acid has lots of acid and not much water so must be handled carefully A strong acid releases lots of H+ A weak acid releases fewer H+
10. What are Bases (Alkalis)? In our home we often use bases to clean things. Eg Bleach and toothpaste Some things are not acids or bases, we say that they are neutral. Eg Water
11. Bases Definition A family of compounds that behave similarly Have a high pH Turn litmus BLUE All donate OH- Examples Ammonia NH3 Sodium Hydroxide NaOH
12. Measuring acid strength? To decide if something is an acid or a base we can use an indicator. Litmus and Universal Indicator are examples of indicators. They change colour depending on if they are in an acid or a base.
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14. Working with Indicators Red litmus turns BLUE in the presence of Bases Blue litmus turns RED in the presence of acid Acids and bases react together in a NEUTRALISATION reaction
