Organic Analysis

• What does acidified potassium dichromate (VI) distinguish between?

  Primary, secondary, and tertiary alcohols
• What happens to secondary alcohols when oxidised by K₂Cr₂O₇?

  They are oxidised to ketones
• What occurs with tertiary alcohols when treated with K₂Cr₂O₇?

  No reaction occurs
• What color change indicates the oxidation of alcohols with K₂Cr₂O₇?

  Orange to green
• What is the procedure for testing alcohols with K₂Cr₂O₇?

  1. Add alcohol to dichromate solution
  2. Warm the mixture gently
  3. Observe the color change
• How do aldehydes and ketones differ in terms of oxidation?

  Aldehydes are easily oxidised; ketones are not
• What is Fehling’s solution used for?

  To differentiate between aldehydes and ketones
• What is the result when ketones react with Fehling’s solution?

  No reaction occurs; solution remains blue
• What is the procedure for conducting Benedict’s test?

  Mix sample with Benedict’s solution and heat
• What is the result of a positive Benedict’s test?

  Solution changes from blue to brick-red
• What are the steps for performing Fehling’s test?

  1. Mix sample with Fehling’s solution
  2. Heat gently
  3. Observe color change
• What is the result when ketones react with Tollens’ reagent?

  No reaction occurs; no silver mirror forms
• What is the procedure for preparing Tollens’ reagent?

  1. Add silver nitrate to test tube
  2. Add sodium hydroxide until brown precipitate forms
  3. Add dilute ammonia until precipitate dissolves
• What confirms the presence of a carboxylic acid?

  Effervescence when reacting with sodium carbonate
• What gas is produced when carboxylic acids react with sodium carbonate?

  Carbon dioxide (CO₂)
• How can the presence of CO₂ be confirmed?

  Bubbling it through limewater
• What characterizes alkenes?

  Unsaturated C=C double bonds
• What is the bromine water test used for?

  To confirm the presence of alkenes
• What does mass spectrometry determine?

  Mass-to-charge ratio (m/z) of ions
• How can the relative molecular mass (M_r) be found?

  By identifying the molecular ion peak
• What does high-resolution mass spectrometry (HRMS) measure?

  m/z of ions with high precision
• How does HRMS differentiate between similar compounds?

  Measures m/z to several decimal places
• What is the significance of the fingerprint region in IR spectroscopy?

  Unique patterns for identifying compounds
• What happens to bonds in organic molecules when they absorb IR radiation?

  They vibrate by stretching, bending, and twisting
• What does infrared spectroscopy measure?

  Changes in atomic vibrations with IR radiation
• What are the steps for conducting an IR spectroscopy analysis?

  1. Irradiate sample with IR radiation
  2. Detect intensity of transmitted IR radiation
  3. Analyze absorption at specific frequencies
• What is the greenhouse effect?

  Natural process warming Earth's surface
• What gases contribute to the greenhouse effect?

  CO₂, methane, and water vapour
• How do greenhouse gases affect heat in the atmosphere?

  They absorb and emit infrared radiation
• What is the result of increased greenhouse gases in the atmosphere?

  Enhanced greenhouse effect leading to global warming
• What are the consequences of global warming?

  Changes in climate patterns and rising sea levels
• What is the fingerprint region in IR spectroscopy?

  Unique region for identifying compounds
• What is the wavenumber range for C=O in IR spectroscopy?

  1680-1750 cm^-1
• What is the wavenumber range for C-H in IR spectroscopy?

  2850-3300 cm^-1
• What is the wavenumber range for C≡N in IR spectroscopy?

  2220-2260 cm^-1
• What is the wavenumber range for O-H (acids) in IR spectroscopy?

  2500-3000 cm^-1
• What is the wavenumber range for C-O in IR spectroscopy?

  1000-1300 cm^-1
• What is the wavenumber range for C=C in IR spectroscopy?

  1620-1680 cm^-1
• What is the significance of the absorption at around 1710 cm^-1 in IR spectroscopy?

  Indicates presence of C=O carbonyl group
• What is the significance of the IR spectrum of propan-2-ol?

  Shows unique absorption patterns for identification