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Answer either part A or part B - Leaving Cert Chemistry - Question c - 2004
Question c
Answer either part A or part B. A Write a brief note on the contribution made to our understanding of crystal structures by (i) Lawrence and William Bragg. (ii) ... show full transcript
Worked Solution & Example Answer:Answer either part A or part B - Leaving Cert Chemistry - Question c - 2004
Step 1
Write a brief note on the contribution made to our understanding of crystal structures by (i) Lawrence and William Bragg.
Answer
Lawrence and William Bragg significantly advanced our understanding of crystal structures through the development of X-ray crystallography. They utilized X-rays to determine the arrangement of atoms within a crystal, providing a method to analyze materials at the atomic level. Their work laid the foundation for modern crystallography, enabling scientists to uncover the structures of various complex substances.
Step 2
Write a brief note on the contribution made to our understanding of crystal structures by (ii) Dorothy Hodgkin.
Answer
Dorothy Hodgkin made remarkable contributions by using X-ray crystallography to solve the structures of complex molecules. Her work included the analysis of important substances such as penicillin and vitamin B12. Through her meticulous methods, Hodgkin obtained valuable insights into molecular configurations, earning her the Nobel Prize in Chemistry.
Step 3
What type of crystal is formed by iodine and what are the binding forces in the crystal?
Answer
Iodine forms a covalent molecular crystal. The binding forces within the iodine crystal are primarily Van der Waals forces, which include London dispersion forces. These weak intermolecular forces enable the iodine molecules to maintain their structure while allowing for a degree of flexibility.
Step 4
Explain (i) why metals are generally good conductors of electricity.
Answer
Metals are generally good conductors of electricity because they possess delocalized electrons, particularly in their outer shells. These electrons can move freely throughout the metal lattice, allowing for the efficient transfer of electrical charge.
Step 5
Explain (ii) why most ionic crystals dissolve in water.
Answer
Most ionic crystals dissolve in water due to the attraction of water molecules to the charged ions in the crystal. The polar nature of water molecules facilitates the overcoming of the ionic bonds holding the crystal together, leading to hydration of the ions and their subsequent dispersion throughout the solution.