Reactions of acids

• acid + metal is what?

  salt + hydrogen
• explain what happens in the reaction of metal and acid in terms of oxidation and reduction

  • metal + acid to form salt + hydrogen
  • hydrogen from the acid has been replaced by the metal
  • metal is oxidised and hydrogen ions are reduced
  • (redox reaction)
• chemical formula for hydrochloric acid

  HCL
• chemical formula for Nitric acid

  HNO₃
• chemical formula for sulphuric acid

  H₂SO₄
• ions in HCL

  • H+
  • Cl-
• ions in HNO3

  • H+
  • NO3-
• ions in H2SO4

  • 2H+
  • So4 2-
• alkalis and bases are what?

  metal hydroxides
• what are alkalis specifically?

  soluable bases (metal hydroxides)
• what are bases ?

  (insoluable)metal hydroxides and metal oxides
• acid + alkali is what?

  salt + water
• acid + base is what?

  salt + water
• acid + metal oxide is what?

  salt + water
• acid + metal carbonate is what?

  salt + water + co2
• how do you name salts?

  • first part comes from metal,base,alkali or carbonate
  • second part comes from the acid: HCL make chloride, Nitric acid makes nitrates and sulphuric acid makes sulphates
• what ion causes acidity?

  H+
• which ions makes a substance alkaline?

  OH-
• what is the pH scale?

  • 0-14
  • measure of acidity/alkalinity of a solution
• how can pH be measured?

  • universal indicator
  • or pH probe
• solution of pH 7 is what?

  neutral
• above pH 7 is what?

  alkaline
• below pH 7 is what?

  acidic
• in neutralisation what happens to the ions to make a neutral solution?

  • H+ react with OH- to produce water
• difference in acidity of pH 1 and 2

  1 is ten time more acidic
• what is a strong acid?

  one that completely ionises in an aqueous solution
• 3 examples of strong acids

  HCL nitric sulphuric
• what is a weak acid?

  one that only partially ionises in an aqueous solution
• 3 examples of weak acids

  ethanoic citric carbonic
• what does ionise mean?

  split up into ions
• which pH are stronger acids

  the stronger the acid the lower the pH (more H+ ions)
• relationship between pH and hydrogen ion conc

  as the pH decreases by one unit the ion conc increases by a factor of 10
• what is a dilute solution?

  small amount of acid per unit volume
• what is a concentrated solution?

  lots of acid per unit volume
• what is the difference between strength and conc?

  strength is how it ionises and conc is the moles of H+ ions