Acids and alkalis

• Dilute acid


  A strong acid that has been mixed with water
• Dilute acid


  Can irritate the skin if it comes into contact with it
• Concentrated acid


  More dangerous than a dilute acid as it is corrosive - which means it can attack metal and destroy skin
• Weak acids


  Such as citric acid, are often found in foods such as lemons and vinegar which have sour tastes
• Base


  A substance that can neutralise an acid. Bases are normally metal oxides, metal hydroxides and metal carbonates
• Alkali


  Bases that do dissolve
• Alkalis


  • Found in common household products such as drain cleaners. They are just as dangerous as concentrated acids
• Weak alkalis


  Found in toothpaste and baking powder
• Alkalis are bases
• Neutralisation


  The process that occurs when an acid and alkali meet
• pH scale


  Determines how acidic or alkaline a substance is. Acids have a pH of 0-6, neutral is pH 7, alkalis have a pH of 8-14
• Universal indicator


  A substance that you can mix with another, the solution will change colour depending on the acidity or alkalinity
• Litmus paper


  A special kind of paper that turns red in acids and blue in alkalis
• pH 0-1


  Strong acids, very acidic
• pH 2-3


  Weak acids, acidic
• pH 7


  Neutral substances, no pH change
• pH 8-9


  Weak bases, slightly basic
• pH 10-12


  Strong bases, very basic
• Neutralization


  A chemical reaction between an acid and a base to form a salt and water.
• Salt naming rule


  A salt is named as the acid (parent) + base (parent)