Untitled Quiz

Analytical Chemistry

• Analytical chemistry is the branch of chemistry that deals with the analysis of different substances, including their separation, identification, and quantification using both classical and modern methods.
• Its main roles include characterizing the composition of matter, both qualitatively and quantitatively, improving established analytical methods, extending existing analytical methods to new types of samples, and developing new analytical methods for various chemical phenomena.
• A sample is anything from air, water, soil, food, living organisms (e.g., rock, meat, water from a tank or river) to tissue or blood from animals or humans. The analysis (analyte) aims to determine the percentage of each substance within it.

Types of Analytical Analysis

• Qualitative analysis: Identifying the components present in a sample. This can include inorganic elements or organic compounds.
  • Identifying the different elements or functional groups in a sample
• Quantitative analysis: Determining the amount of each component in a sample. This determines the numerical quantification of the different elements or compounds present in a sample.
  • Volumetric analysis (Titrimetry): Measures the volume of reagent
  • Gravimetric analysis: Determines the mass of the analyte
  • Instrumental analysis: Uses instruments to measure physical or chemical properties related to the amount of substances in a material.
    • Spectroscopic methods: Involve measuring interactions with electromagnetic radiation (e.g., UV-Vis, IR, NMR, mass spectrometry)
    • Electroanalytical methods: Measuring various electrical properties of materials (e.g., pH, electro deposition, voltametry, etc.)

Classification of Analytical Methods

• Classical methods: Traditional techniques, including titrimetry and gravimetry.
• Modern methods: Instrumental techniques, relying on advanced instruments. These methods are often used in combination with each other.
  • Qualitative: Qualitative analysis methods
  • Quantitative: Quantitative analysis methods

Separation Techniques

• Separation methods are used for isolating specific components from complex mixtures. These methods frequently utilize instruments for separation.
  • Precipitation
  • Volatilization
  • Ion Exchange
  • Solvent Extraction
  • Chromatography

Modern Analytical Chemistry

• Modern analytical chemistry is heavily dominated by instrumental techniques.
• There are numerous techniques with specialized instruments.
• This can result in a seemingly complex array but in many cases combines methods.

Hybrid Techniques

• Combining techniques produces hybrid methods like gas chromatography-mass spectrometry for comprehensive analysis.

Microscopy

• Microscopy is crucial for visualizing various materials at various scales, including single molecules, cells, and biological tissues.
• Optical microscopy: Using light
• Electron microscopy: Using electrons
• Scanning probe microscopy: Scanning at a very high resolution

Lab-on-a-chip (microfluidics)

• Miniaturized analytical systems allow for analysis on a chip or within microfluidic devices

Standard Curves

• Standard curves are used to determine the concentration of an unknown substance based on known concentrations.
• This is achieved by analyzing and comparing standards with samples of unknown concentrations.

Solutions

• Solutions are mixtures of two or more substances, with one substance being the solute (dissolved) and the other solvent (dissolving).

Classification of Solutions

• Unsaturated solutions: Solute amount is below solubility limit.
• Saturated solutions: Solute amount equals the solubility limit.
• Super saturated solutions: Solute amount exceeds solubility limit.

Stoichiometric Calculations

• Calculations involve determining atomic weights, gram atomic weights, formula weights, molecular weights, and Avogadro's number to understand and describe chemical reactions.

Mole Concept

• Mole: Avogadro's number of particles (atoms, molecules, etc.).
• Calculating the number of moles in a given mass

Molarity/Concentration

• Molarity (M): Moles of solute per liter of solution.

Diluting Solutions

• Calculating the needed volume of stock solution for obtaining desired concentrations of diluted solution, this typically involves standard solution methodologies

Normality

• Normality (N): Equivalent of solute per liter of solution