Purity, formulations and chromatography

• What is step 1 of the process of Paper Chromatography?

  Draw a start line on paper and spot the mixture on the line.
• What is step 2 of the process of Paper Chromatography?

  Fill a beaker with solvent below the line and hang paper in the beaker.
• What is step 3 of the process of Paper Chromatography?

  The solvent travels up, separating components.
• What is step 4 of the process of Paper Chromatography?

  Mark the finish line before the solvent reaches the end.
• What is the final step of the process of Paper Chromatography?

  The paper is in a stationary phase whilst the solvent is in a mobile phase.
• Describe the first step of the process of flame emission spectroscopy.

  Identify the cations (metal ions) in the solution.
• Describe the second step of the process of flame emission spectroscopy.

  Measure the exact wavelength of the emitted light. Allow for definite identification.
• Describe the third step of the process of flame emission spectroscopy.

  Concentrations can be found by measuring the light intensity.
• Describe the final step of the process of flame emission spectroscopy.

  Use an intensity vs concentration graph for readings.
• What is a pure substance?

  A single element or compound
• How do pure substances behave in terms of melting and boiling points?

  They melt and boil at specific temperatures
• How can melting and boiling point data be used?

  To distinguish pure substances from mixtures
• What does the term 'pure substance' imply in everyday language?

  It means unadulterated and in its natural state
• What is a formulation?

  A mixture designed as a useful product
• Why are formulations made by mixing components in measured quantities?

  To ensure the product has required properties
• What is chromatography used for?

  To separate mixtures and identify substances
• What are the two phases involved in chromatography?

  A stationary phase and a mobile phase
• What does the separation in chromatography depend on?


  The distribution of substances between phases
• What is the formula for Rf value in chromatography?

  Rf value = (Distance moved by substance)/(Distance moved by solvent)
• How do different compounds behave in chromatography?

  They have different Rf values in different solvents
• What happens to compounds in a mixture during chromatography?

  They may separate into different spots
• What is the result of a pure compound in chromatography?

  It produces a single spot in all solvents
• What is a pigment?

  A solid, coloured substance
• What does paper chromatography separate in a colored substance?

  Different pigments
• What is the stationary phase of Paper Chromatography?

  The phase that stays fixed in place during the chromatography process. It is usually a solid or a viscous liquid that is coated onto a solid support. The stationary phase interacts with the components of the mixture, slowing down their movement based on their different affinities to it.
• What is the mobile phase of Paper Chromatography?

  The phase that moves through or along the stationary phase, carrying the mixture with it. The mobile phase is typically a liquid or gas that flows over or through the stationary phase. It helps to transport the different components of the mixture at varying rates, depending on how much they interact with the stationary phase.