8.1 Purity, formulations, and chromatography

• High purity is critical for safety and quality control in industries like pharmaceuticals.


  True
• What is the melting point of a substance?

  Solid turns to liquid
• What are the two phases used in paper chromatography?

  Stationary and mobile
• What material is used as the stationary phase in thin-layer chromatography?

  Silica gel
• What factors determine the choice of a method for determining chemical purity?

  Precision and resources
• Thin-layer chromatography uses a thin layer of silica gel as the stationary phase.
• What is the purpose of a pump in HPLC?

  To force mobile phase
• Match the method with its characteristics:

  Measuring melting/boiling points ↔️ Low cost and simple use

  Paper chromatography ↔️ Moderate accuracy and ease

  TLC ↔️ Moderate cost and accuracy

  HPLC ↔️ High cost and accuracy
• Formulations stabilize products by preventing degradation


  True
• What are four common types of formulations mentioned in the study material?

  Tablets, creams, liquids, sprays
• Formulations often combine active ingredients with inactive excipients to enhance stability and user experience
• Why is high chemical purity essential in industries like pharmaceuticals?

  Safety and quality control
• What is the melting point of a substance?

  Temperature solid turns to liquid
• What is the accuracy of measuring melting and boiling points to determine purity?

  Relatively low
• What does chemical purity refer to?

  Free from impurities
• Match the property with the type of substance:

  Composition | ↔️ Single, well-defined chemical |

  Safety | ↔️ Well-understood, controlled |

  Properties | ↔️ Consistent, predictable |
• Pure substances have sharp, defined melting and boiling points.


  True
• Substances in paper chromatography separate based on solubility and affinity.

  True
• High-performance liquid chromatography uses a pump to force a liquid mobile phase through a column
• Impurities in a substance can reduce its effectiveness and alter its properties
• Impurities cause a range of melting and boiling points

  True
• HPLC offers high resolution and precise quantification
• What is the primary purpose of formulations?

  To enhance product properties
• Match the industry with an example of its formulation:

  Pharmaceuticals ↔️ Tablet with coating

  Cosmetics ↔️ Moisturizer with emulsifiers

  Agriculture ↔️ Herbicide with surfactants
• Tablets are a common formulation type that combines active drugs with fillers and binders
• Liquid formulations offer rapid absorption and are easy to swallow.


  True
• What does chemical purity refer to?

  Degree of freedom from impurities
• A pure substance has a single, well-defined chemical composition
• Pure substances have sharp and defined melting and boiling points.


  True
• Measuring melting and boiling points is a simple method for determining purity.


  True
• Paper chromatography offers moderate accuracy in determining purity.

  True
• High-performance liquid chromatography (HPLC) uses a pump to force a liquid mobile phase through a column
• What effect do impurities have on melting and boiling points?

  Range of points
• What are the two phases used in paper chromatography?

  Stationary and mobile
• What is used as the stationary phase in thin-layer chromatography (TLC)?

  Silica gel
• What device forces the mobile phase through the column in HPLC?

  Pump
• Order the methods for determining purity from lowest to highest cost.

  1️⃣ Melting/boiling points

  2️⃣ Paper chromatography

  3️⃣ Thin-layer chromatography

  4️⃣ High-performance liquid chromatography
• What is used as the stationary phase in thin-layer chromatography (TLC)?

  Silica gel
• What are the therapeutic or functional substances in formulations called?

  Active ingredients
• Formulations can enhance properties by improving solubility, absorption, or effectiveness