Chemistry Demonstration Interview

This paragraph introduces the format of the demonstration interview, emphasizing the use of Teams and Miro for a more interactive experience. It highlights the importance of being familiar with Miro and its functionalities prior to the interview. The speaker advises candidates to ensure a stable internet connection and a quiet environment for the interview. The main goal of the interview is to select candidates who are best suited for the course, focusing on their ability to apply knowledge rather than their prior knowledge. The speaker encourages candidates to practice explaining chemistry concepts and to be prepared to engage with unfamiliar material during the interview.

The paragraph begins with the interviewers introducing themselves and explaining the structure of the interview. Susan Perkin, a physical chemist, and Professor Steve Faulkner, an inorganic chemist, will be conducting the interview. They explain that the interview will last about 20 minutes and will involve using the Miro board. The interviewers encourage the candidate to communicate any technical issues or lack of understanding during the interview. The interview starts with a question about water, aiming to assess the candidate's understanding of molecular structure and properties.

This section delves into a detailed discussion about atomic and molecular orbitals, specifically focusing on how they might overlap to form bonds within a water molecule. The candidate is guided through thinking about the spatial arrangement of orbitals and how they contribute to bonding. The conversation involves exploring the concept of constructive and destructive interference of electron clouds, leading to the formation of bonding and antibonding orbitals. The candidate demonstrates understanding by correctly identifying the number of lone pairs and bonds in a water molecule and discussing the implications of these findings.

The discussion shifts to the properties of water in its different phases, particularly focusing on the behavior of water in liquid and solid states. The candidate is asked to consider the equilibrium between liquid water and ice at atmospheric pressure and to identify the temperature at which this equilibrium occurs in Kelvin. The conversation explores the concept of density in relation to the phase of water, leading to the conclusion that liquid water is denser than ice. The candidate is encouraged to think about the role of hydrogen bonding in this density difference and to relate it to everyday experiences.

This part of the interview focuses on rationalizing why liquid water is denser than ice, based on the candidate's understanding of hydrogen bonding and molecular arrangement. The candidate suggests that the constant movement of water molecules in the liquid state prevents all hydrogen bonds from being fully formed at any given instant, allowing for a more compact arrangement and thus higher density. The interviewers commend the candidate's ability to connect the molecular-level understanding to the macroscopic properties of water, such as its density and the fact that ice floats on water.

The interview concludes with the interviewers reflecting on the candidate's performance. They discuss the candidate's ability to engage with new concepts, such as atomic and molecular orbitals, and to apply this knowledge to solve problems. The interviewers appreciate the candidate's clear thinking and communication skills, emphasizing the importance of being able to articulate one's thought process and understanding during the interview. They also highlight that there is no disadvantage in not knowing something beforehand, as long as the candidate can work through the information provided and demonstrate their reasoning abilities.