Acids

• Carboxylic acids


  • Ethanoic acid
  • Propanoic acid
  • Butanoic acid
• ethanol


  ethanoic acid
• Weak acid


  HX only a small fraction of molecules ionise to H+ and X-
• Reactions of carboxylic acids

  With carbonates - gentle fizzing
• Reactions of alcohols


  With alcohols (with conc H2SO4 catalyst) - makes esters
• Reactions of carboxylic acids

  1. Carboxylic acid (ethanoic acid)

  2. Alcohol (ethanol)

  3. Ester (ethyl ethanoate)
• Ciliary muscle


  • A ring of muscle that contracts and relaxes to change the shape of the lens
• Suspensory ligaments


  • Ligaments that connect the ciliary muscle to the lens
• Sclera


  • The strong outer wall of the eyeball that helps to keep the eye in shape and provides a place of attachment for the muscles that move the eye
• Fovea


  • A region of the retina with the highest density of cones (colour detecting cells) where the eye sees particularly good detail
• Aqueous humour


  The watery liquid between the cornea and the lens
• Vitreous humour


  The jelly-like liquid filling the eyeball
• Choroid


  • A pigmented layer of tissue lining the inside of the sclera that prevents the reflection of light rays inside the eyeball
• Blind spot


  The point at which the optic nerve leaves the eye, where there are no receptor cells