Rate Constant: A level Chemistry Definition

Alexandra Brennan

Written by: Alexandra Brennan

Reviewed by: Philippa Platt

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What is the rate constant?

In A Level Chemistry, the term 'rate constant' refers to the proportionality factor in the rate equation that links the rate of a chemical reaction to the concentrations of the reactants involved. Denoted by the symbol 'k', the rate constant is specific to a particular reaction at a given temperature and provides insights into the reaction's speed. It remains constant for a reaction under constant conditions, although it typically increases with temperature due to the added energy facilitating more frequent and effective particle collisions. The units of the rate constant vary depending on the order of the reaction, playing a crucial role in determining the reaction rate using the rate equation.

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Alexandra Brennan

Author: Alexandra Brennan

Expertise: Chemistry

Alex studied Biochemistry at Newcastle University before embarking upon a career in teaching. With nearly 10 years of teaching experience, Alex has had several roles including Chemistry/Science Teacher, Head of Science and Examiner for AQA and Edexcel. Alex’s passion for creating engaging content that enables students to succeed in exams drove her to pursue a career outside of the classroom at SME.

Philippa Platt

Author: Philippa Platt

Expertise: Chemistry

Philippa has worked as a GCSE and A level chemistry teacher and tutor for over thirteen years. She studied chemistry and sport science at Loughborough University graduating in 2007 having also completed her PGCE in science. Throughout her time as a teacher she was incharge of a boarding house for five years and coached many teams in a variety of sports. When not producing resources with the chemistry team, Philippa enjoys being active outside with her young family and is a very keen gardener

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