Question 1: The Avogadro Constant is the number of particles (atoms, molecules, or ions) in one mole of a substance. Its value is approximately 6.022 x 10^23 particles per mole. This constant allows chemists to relate the microscopic world to the macroscopic amounts measured in the laboratory.

Answer: 6.022 x 10^23 particles per mole

Question 1: Define the term 'mole' in chemistry.

Answer: A mole is the amount of substance containing exactly 6.022 x 10^23 particles.

Question 2: Explain why the Avogadro Constant is important in chemical calculations.

Answer: It allows chemists to convert between the number of particles and the amount of substance in moles, linking microscopic particles to macroscopic measurements.

Question 1: Calculate the number of molecules in 2.5 mol of water (H₂O).

Answer: 1.505 x 10^24 molecules

Question 2: A sample contains 3.01 x 10^23 particles. How many moles does this correspond to? (Use Avogadro's Constant = 6.022 x 10^23).

Answer: 0.5 mol

Question 1: Describe a basic experimental method to determine the molar mass of a substance using the Avogadro Constant.

Answer: We measure a sample's mass, convert it to moles by dividing by the molar mass, and then determine the number of particles using the Avogadro Constant to find the molar mass.

Question 2: Identify two safety precautions that should be observed when handling substances in mole-related experiments.

Answer: Wear appropriate personal protective equipment and handle chemicals in a well-ventilated area.

Question 1: A sample of sulphur weighs 32.06 grams, which is 1 mole of sulphur atoms. Calculate the number of sulphur atoms in this sample.

Answer: 3.613 x 10^24 atoms

Question 2: If a chemist has 1.204 x 10^24 molecules of a substance, how many moles does this represent?

Answer: 0.2 mol

Question 1: Explain how the Avogadro Constant links the microscopic world of particles to the macroscopic world of measurable quantities. Include in your answer the significance for calculating molecular and formula masses. (6 marks)

Answer: The Avogadro Constant (6.022 x 10^23) represents the number of particles in one mole of a substance. It enables chemists to relate the mass of a substance to the number of particles it contains, facilitating calculations of molecular and formula masses. This linkage is essential for converting between microscopic particles and measurable quantities like grams, thus allowing precise quantitative analysis in chemistry.

Question 1: Describe how the Avogadro Constant is used in the pharmaceutical industry when preparing medication doses.

Answer: It helps determine the number of molecules or atoms in a given dose, ensuring accurate and consistent medication preparation based on molecular quantities.

Question 2: Explain the role of the Avogadro Constant in developing new materials, such as nanomaterials or polymers.

Answer: It allows scientists to relate the number of molecules or atoms in a given sample, aiding in designing materials with specific molecular structures and properties.