Acids and Bases - PowerPoint PPT Presentation

acids and bases n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Acids and Bases PowerPoint Presentation
Download Presentation
Acids and Bases

play fullscreen
1 / 10
Acids and Bases
218 Views
Download Presentation
stu
Download Presentation

Acids and Bases

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Acids and Bases Acids and Bases

  2. Acids Acidsgenerally have certain properties… • (a) Have a SOUR taste • (b) Change the colour of litmus indicator from BLUE to RED • (c) Conduct ELECTRICITY • (d) CORRODE most metals • (f) NUTRALISEbases. Acids are often found in foods

  3. Bases Bases generally have certain properties… (a) Have a BITTER taste (b) Change the colour of litmus indicator from REDto BLUE (d) have a SOAPY feel (e) NUTRALISE acids. BASES are also called alkalis. Bases are generally used as cleaning agents

  4. Common Acids and Bases

  5. The pH Scale • The strength of acids and bases is measured on the “pH scale”. • Pure water has a pH value of 7, because it is neither acidic or basic, its Neutral. • Acids have a pH < 7 • Bases have a pH > 7 • The further away from 7 the pH gets, the stronger the acid or base. The strength of acids and bases is measured on the “pH scale”. Pure water has a pH value of 7, because it is neither acidic or basic, its Neutral. Acids have a pH < 7 Bases have a pH > 7 The further away from 7 the pH gets, the stronger the acid or base.

  6. Common pH Values

  7. Indicators • An indicator is a chemical, or mixture of chemicals that react and change colour in the presence of an acid or a base. • Common indicators include: • Universal indicator • Methyl orange • Litmus • Phenolpthalein • Bromothymol blue

  8. Common Indicators

  9. Universal Indicator Universal Indicator is a mixture of indicators and it allows us to not only determine whether the substance is an acid or base, but it gives some idea of the actual pH of the solution….

  10. What have you learnt??? Questions • List the following as either an acid or base and put them in order from strongest to weakest: • pH 12, pH 5 pH 5.5, pH 1, pH 7, pH 9, pH 3 • Where is the most common place to find an acid and a base? • What is the pH of a substance that is neutral? • List 3 properties of an acid • List 3 properties of a base