chemistry - acids, bases and salts

• what is the pH scale used to determine?

  a substance is an acidic, alkaline or neutral
• what is the universal indicator used to determine?

  what substance it is by the colour change
• what do acids have a lower pH than? (number)

  7
• what do acids contain?

  Hydrogen ions
• the higher the concentration if hydrogen ion, the what?

  stronger the acid (lower pH)
• what do alkaline have a higher pH than? (number)

  7
• what do alkaline contain?

  Hydroxide ions
• the higher the concentration of hydroxide ions, the what?

  stronger the alkali (higher pH)
• what is litmus paper used for?

  detect if something is acidic or alkaline
• what does red litmus paper turn when in alkaline solution?

  Blue
• what does blue litmus paper turn when in a acidic solution?

  Red
• the name of the salt formed in a reaction with an acid has 2 parts. what are they?

  1. name of the metal
  2. the acid (changes depending of what salt is used)
• what is the word equation for reacting metals with acids?

  metal + acid -> metal salt + hydrogen
• what are the 2 key observations of reacting metals with acids?

  1. metal will dissolve
  2. effervescence as gas is produced
• what is the word equation for reacting metals carbonates with acids?

  Metal carbonate + acid → salt + water + carbon dioxide
• what is the key observation when reacting metal carbonate with acid?

  effervescence
• what is the word equation for reacting acids with bases?

  acid + metal oxide -> salt + water

  OR

  acid + metal hydroxide -> salt + water
• what might you observe when reacting bases with acids?

  colour change
• when reacting bases with acids, what type of reaction is it?

  Neutralization
• what are the steps of making a salt?

  1. add excess powder to acid - ensure acid has reacted
  2. filtration - removing the unreacted powder
  3. evaporation - losing the water
• what are titrations used to find?

  Concentration of acid or alkali
• how would you neutralise an acid or alkali?

  have a known volume of one and work out the volume needed
• what would you use to know when neutralisation has been reached?

  pH indicator