biochemistry

• Acidic solutions


  pH between 1-7
• Neutral solutions


  pH of 7
• Alkaline (basic) solutions


  pH between 7-14
• pH scale


  Measures the acidity or alkalinity of a solution
• Common acids


  • Hydrochloric acid
  • Nitric acid
  • Sulphuric acid
• Hydrogen ions


  Found in all acids
• Acid + metal oxide


  Salt + water
• Acid + metal hydroxide


  Salt + water
• Household acids


  • Vinegar
  • Lemon juice
• Household bases


  • Laundry detergent
  • Baking soda
• Acid solutions


  Contain hydrogen ions and are not molecular
• Alkaline solutions


  Contain hydroxide ions and are not molecular
• Indicator


  Substance that changes colour depending on the pH of a solution
• Universal indicator


  • Red in acidic solution
  • Blue in an alkaline solution
  • Green in a neutral solution
• Litmus indicator solution


  • Turns red in acidic solutions and blue in alkaline solutions
• Base


  Substance that reacts with an acid to form a salt and water
• Base


  • Copper oxide
• Alkali


  Soluble base with pH greater than 7
• Alkali


  • Sodium hydroxide
• Neutralisation reaction


  Occurs when an acid reacts with an alkali
• Salts formed with acids

  • Chlorides (from hydrochloric acid)
  • Sulphates (from sulphuric acid)
  • Nitrates (from nitric acid)
• Salt formed


  • Copper sulfate (from copper oxide and sulphuric acid)
• Hydrochloric acid + sodium hydroxide


  Sodium chloride + water
• Sulfuric acid + sodium hydroxide


  Sodium sulfate + water
• Ionic bonding - atoms from a metal become positive ions and the non-metal atoms become negative ions and the metal ions are transferred to the non-metal , there is a strong electromagnetic force between the oppositely charged ions, resulting in an ionic bond

  
• covalent bonding - when two non-metals share a pair of electrons from the outer shell.

  
• metallic bonding - is the force of attraction between free moving (delocalised) electrons and positive metal ions.

  
• metals and non-metals are formed during ionic bonding.
• when an ionic bond forms one or more electrons is transferred from a metal atom to a non-metal atom.
• ions are the particles present in an ionic bond
• electrostatic forces attract oppositely charged ions to each other
• non-metals are the element formed during covalent bonding
• how are the electrons re-arranged in a single covalent bond?

  A pair of electrons is shared between two atoms. These electrons are found in the outer shells of the atoms, each atom contributes one electron to the shared pair of electrons.
• the two types of particles formed in a metallic bond are positive metal ions and negative electrons.
• why do metal ions have a positive charge?


  metal atoms lose negatively charged electrons to form metal ions. There are now more positively charged protons in the atom than negatively charged electrons and the metal ion has an overall positive charge.
• what forces attract the particles to each other

  electrostatic
• what types of elements are involved in ionic bonding?

  metals and non-metals
• what type of elements are involved in covalent bonding?

  non-metals only
• what type of elements are involved metallic bonding?

  metals only
• electrons are shared in covalent bonding