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Slide 1

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Alkali metal + water -> metal hydroxide and hydrogen
· Alkali metals react with group 7 to form white or colourless salt crystals
· Alkali metal compounds dissolve in water to form colourless solutions
· At room temperature: Fluorine ­ pale yellow gas ; Chlorine ­ green gas ; Bromine ; red/brown liquid ;
Iodine ­ grey solid or vaporises to lilac gas
· Halogens form ionic compounds with metals ­ these halides have a charge of -1
· Halogens bond covalently with non-metals ­ these form molecules
· Soap + hard water -> scum
· Temporary hard water + heat -> scale ; soften by boiling since hydrogencarbonate ions decompose when
heated to produce carbonate ions, carbon dioxide and water. The carbonate ions react with the calcium
or magnesium to produce an insoluble solid which is then removed.
· Add washing soda to temporary or hard water ; reacts to form solid calcium and magnesium that don't
react with soap ; use ion-exchange column
· Fuel + food -> exothermic reaction
· Positive ions identified by flame test or sodium hydroxide solution ; Lithium ­ red flame ; Sodium ­
yellow flame ; Potassium ­ lilac flame ; Calcium ­ red flame ; Barium ­ green flame ; Copper (ii)
hydroxide ­ blue ; Iron (ii) hydroxide ­ green ; Iron (iii) hydroxide ­ brown
· Hydroxides of metals with +2 or +3 are insoluble in water
· Sodium hydroxide + metal hydroxide -> metal hydroxide precipitate
· Aluminium, calcium and magnesium form a white precipitate
· Precipitate + sodium hydroxide solution -> precipitate dissolves…read more

Slide 2

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Carbonate ions: add dilute hydrochloric acid ­ if it fizzes and turns cloudy, substance contains carbonate
ions
· Halide ions: add dilute nitric acid then silver nitrate solution. Chloride ions ­ white precipitate ; Bromide
ions ­ cream precipitate ; Iodine ions ­ yellow precipitate
· Sulfate ions ­ Add dilute hydrochloric acid then barium chloride solution. If white precipitate forms,
sulfate ions are present.
· Acid + alkali -> salt + water
· Equilibrium ­ rate of forward reaction = rate of backward reaction
· Alcohols with smaller molecules like ethanol react with water to form neutral solutions. Organic
substances dissolve in alcohols.
· Alcohols burn in air. When combustion has taken place, carbon dioxide and water are produced.
(ethanol + oxygen -> carbon dioxide + water)
· Sodium + alcohol -> hydrogen
· Alcohol + potassium dichromate -> oxidised to carboxylic acid
· Carboxylic acids and esters + water -> pH less than 7 (acidic)
· Carboxylic acid + carbonate -> carbon dioxide + salt + water
· Alcohol + carboxylic acid -> (using acid catalyst) ester such as ethyl ethanoate + water
· Strong acids ­ in aqueous solutions, ionise completely
· Weak acids ­ in aqueous solutions, do not ionise completely (higher pH and react more slowly than
strong acids)…read more

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