1 / 11

Do Now:

Do Now:. Complete the empirical formula worksheet. Ask someone that was in P5 Science yesterday for help if you don’t understand. . Flame Tests And Precipitation Reactions. . Flame Tests: . Describe flame tests to identify metal ions. . http:// www.youtube.com/watch?v=rEWLFH-QpWE Method:

percy
Download Presentation

Do Now:

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Do Now: • Complete the empirical formula worksheet. • Ask someone that was in P5 Science yesterday for help if you don’t understand.

  2. Flame Tests And Precipitation Reactions.

  3. Flame Tests: • Describe flame tests to identify metal ions. • http://www.youtube.com/watch?v=rEWLFH-QpWE • Method: • dip a clean flame test loop in the sample solution • hold the flame test loop at the edge of a Bunsen burner flame • observe the changed colour of the flame, and decide which metal it indicates • clean the loop in acid and rinse with water, then repeat steps 1 to 3 with a new sample

  4. Flame Tests • Describe flame tests to identify metal ions.

  5. Precipitation Reactions lead nitrate sodium chloride lead chloride sodium nitrate + +  + + Pb(NO3)2(aq) 2NaCl (aq)  PbCl2 (s) 2NaNO3 (aq) Sometimes when two solutions are mixed, they react to form an insoluble solid product. The insoluble solid product is called a precipitate. You can spot a precipitate because the mixture goes cloudy. For example, mixing solutions of lead nitrate and sodium chloride produces a yellow precipitate of lead chloride.

  6. If you get a white precipitate: Add more sodium hydroxide solution, aluminium precipitate will dissolve.If the white precipitate does not dissolve then the metal ion is calcium or magnesium. These can be distinguished using a flame test(magnesium ions have no flame colour). What colour would we get for a flame test for Calcium ions?

  7. aluminiumchloride + sodium hydroxide aluminiumhydroxide + sodiumchloridealuminiumchloride + sodium hydroxide aluminiumhydroxide + sodiumchloride AlCl3(aq)          +          3NaOH(aq)Al(OH)3(s)      +      3NaCl(aq) The ionicequation is    Al3+(aq)  +  3OH-(aq)Al(OH)3(s) Aluminiumhydroxide is white. calciumchloride + sodiumhydroxide calciumhydroxide + sodiumchloride. CaCl2(aq)         +         2NaOH(aq)Ca(OH)2(s)     +     2NaCl(aq) The ionicequation is    Ca2+(aq)  +  2OH-(aq)Ca(OH)2(s) Calciumhydroxide is white.

  8. magnesium chloride + sodium hydroxide magnesium hydroxide + sodium chloridemagnesium chloride + sodium hydroxide magnesium hydroxide + sodium chloride MgCl2(aq)          +          2NaOH(aq)Mg(OH)2(s)      +      2NaCl(aq) The ionicequation is    Mg2+(aq)  +  2OH-(aq)Mg(OH)2(s) Magnesiumhydroxide is white. copper(II) chloride + sodium hydroxide copper(II) hydroxide + sodium chloride CuCl2(aq)          +          2NaOH(aq)Cu(OH)2(s)      +      2NaCl(aq) The ionicequation is    Cu2+(aq)  +  2OH-(aq)Cu(OH)2(s) Copper(II) hydroxide is blue.

  9. iron(II) chloride + sodiumhydroxideiron(II) hydroxide + sodiumchloride.iron(II) chloride + sodiumhydroxideiron(II) hydroxide + sodiumchloride. FeCl2(aq)         +         2NaOH(aq)Fe(OH)2(s)     +     2NaCl(aq) The ionicequation is    Fe2+(aq)  +  2OH-(aq)Fe(OH)2(s) Iron(II) hydroxide is green. iron(III) chloride + sodiumhydroxideiron(III) hydroxide + sodiumchloride FeCl3(aq)         +          3NaOH(aq)Fe(OH)3(s)      +      3NaCl(aq) The ionicequation is    Fe3+(aq)  +  3OH-(aq)Fe(OH)3(s) Iron(III) hydroxide is brown.

  10. Applications: Most precipitation reactions are very fast reactions that occur between ions. This makes them very useful for identifying specific ions based on the type of precipitate formed. • Precipitation reactions have a number of other uses: • production of coloured pigments for paints and dyes • removal of toxic chemicals from water • separation of reaction products. A lead iodide precipitate.

  11. Reactions of Carbonates • All metal carbonates react with dilute hydrochloric acid to produce Carbon Dioxide. • Write the reactions of Calcium Carbonate, Sodium Carbonate and Magnesium carbonate with Hydrochloric acid: • Remember to write word then balanced symbol equations – check, the group numbers to help you to balance the equations. • Carbon dioxide precipitates Limewater: • Can you remember the reaction for this (C1 Limestone cycle).

More Related