Chemistry HL Chapter 11

  1. What is systematic error?
    • Error in the calibration (accuracy)
    • Can’t be reduced through multiple readings.
  2. What is random error?
    • Error that can be equally high or low (precision)
    • Can be reduced through multiple readings.
  3. How do we use absolute and percentage uncertainties?
    • Addition: Absolute uncertainties are simply added.
    • Division, multiplication: Percentage uncertainties are added and converted back into an absolute uncertainty
  4. How is total error calculated?
    Literature value - calculated value over literature value
  5. How to calculate IHD (Index of hydrogen deficiency)
    • Each double bond counts as one IDH and each triple bond 2 IDH
    • If x is the number of carbon and y the number of hydrogen
    • (2x+2-y)/2 gives us the IDH
    • For each N, add one to both x and y
    • Other compounds don’t affect the IDH
  6. What are the properties of HNMR
    • Number of peaks gives the number of different chemical environments occupied by H.
    • Area under each peak gives the number of protons in that specific chemical environment.
    • The standard is TMS because it produces a single strong peak and can easily be removed as it’s volatile.
    • Each peak is split into n+1 peaks, n being the number of protons bonded to the adjacent carbon due to split split coupling.
    • Incredibly powerful tool for structural determination and determining isomers (cis or trans)
    • Used in MRI technology
  7. X-Ray crystallography
    • Used to determine exact position of atoms and thus the exact structure of compound.
    • It identifies
    • Bond lengths
    • Bond angles
    • Chemical structure of the compound
Card Set
Chemistry HL Chapter 11