acids, bases and salts

ACIDS, BASES AND SALTS

All acids produce H+ aq ions when dissolved in water. Acids are NEUTRALIZED by BASES such as METAL OXIDES and METAL HYDROXIDES. 

alkalis are soluble bases and all alkalis contain OH- aq ions.

            INDICATORS                           acid              alkalinelitmus paper         pink              bluemethyl orange      red                yellowphenolphthalein    colourless      pink

pH scale- 0= really acidic14= really alkaline7= neutral

In order for an acid to form, water must be involved to break up the ions e.g. hydrogen chloride + water --> hydrochloric acid

          SOLUBILITY RULES all sodium and ammonium salts are soluble. all nitrates are soluble most chlorides, bromides and iodides are soluble most sulfates are soluble except barium and lead most carbonates are insoluble except sodium, potassium and ammonium salts 

MAKING INSOLUBLE SALTS BY PRECIPITATION 

Mix two appropriate soluble salt solutions e.g. for lead chloride you would need to choose a solution contain lead inos and one with chloride ions. choose a nitrate and a sodium salt because these are ALWAYS soluble e.g. lead nitrate solution and sodium chloride solution. lead nitrate + sodium chloride --> lead chloride + chloride solution  filter, wash and dry the solid precipitate.  

MAKING SALTS USING ACIDS

ACID + METAL --> A SALT + HYDROGEN this is not suitable for making salts using group 1 metals because they are too reactive. ACID + BASE --> A SALT + WATER This is not suitable for soluble bases. This reaction might need warming up to speed up the rate. ACID + METAL CARBONATE --> A SALT + WATER + CARBON DIOXIDE  

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