Qualitative Analysis - any method used to identify which chemical substances are present, eg, using an indicator to find out if acids are present.
Quantitative Analysis - any method used to determine the amount of a particular chemical substance present, for example, carrying out an acid-base titration to find out how much acid is present.
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Identifying Hydrogen Ions (H )
The presence of a Hydrogen ion means that the substnace is an acid. The more hydrogen ions that there are the stronger the acid, and therefore the lower the pH on the pH scale.
The pH of a substance can be measured using an indicator such as litmus solution (universal indicator) or litmus paper.
Purple and blue litmus paper will turn red if the substance is an acid.
Common acidic substances include...
Hydrochloric Acid (HCl)
Sulphuric Acid (H SO )
Nitroc Acid (HNO )
When an acidic substance dissolves in water (aq) it produces H ions.
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Acid Reactions
Acid + Metal --> Salt + Hydrogen
Acid + Metal Carbonate --> Salt + Water + Carbon Dioxide
Acid + Alkali --> Salt + Water
Acid + Metal Oxide --> Salt + Water
Remember:
Hydrochloric Acid makes chloride salts,
Sulpuric Acid makes sulphate salts,
Nitric Acid makes nitrate salts.
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Identifying Substances
Qualitative Analysis - any method used to identify which chemical substances are present, eg, using an indicator to find out if acids are present.
Quantitative Analysis - any method used to determine the amount of a particular chemical substance present, for example, carrying out an acid-base titration to find out how much acid is present.
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Identifying Ions Using Flames
When held in a Bunsen flame, different metals burn with different distinctive flames:
Sodium (Na ) = Yellow Flame
Potassium (K ) = Lilac Flame
Calcium (Ca ) = Brick-Red Flame
Copper (Cu ) = Blue-Green Flame
Therefore,
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Identifying Hydrogen Ions (H )
The presence of a Hydrogen ion means that the substnace is an acid. The more hydrogen ions that there are the stronger the acid, and therefore the lower the pH on the pH scale.
The pH of a substance can be measured using an indicator such as litmus solution (universal indicator) or litmus paper.
Purple and blue litmus paper will turn red if the substance is an acid.
Common acidic substances include...
Hydrochloric Acid (HCl)
Sulphuric Acid (H SO )
Nitroc Acid (HNO )
When an acidic substance dissolves in water (aq) it produces H ions.
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Acid Reactions
Acid + Metal --> Salt + Hydrogen
Acid + Metal Carbonate --> Salt + Water + Carbon Dioxide
Acid + Alkali --> Salt + Water
Acid + Metal Oxide --> Salt + Water
Remember:
Hydrochloric Acid makes chloride salts,
Sulpuric Acid makes sulphate salts,
Nitric Acid makes nitrate salts.
7 of 8
Identifying Ions Using Flames
When held in a Bunsen flame, different metals burn with different distinctive flames:
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