Chemistry – Science and Joe

Miller-Urey: A Key Experiment in Understanding Life’s Beginnings

21st Aug 2026

The discovery of DNA’s three-dimensional double helical structure in 1953 was amazing. However, other very important scientific discoveries were also made that year, including via the Miller-Urey Experiment. The Miller-Urey experiment, conducted by American scientists Stanley Miller and Harold C. Urey, aimed to replicate the conditions on very early Earth to understand the origin of … More Miller-Urey: A Key Experiment in Understanding Life’s Beginnings

Understanding Relative Atomic Mass: A Complete Guide

4th Aug 2026

What is relative atomic mass and how is it calculated? Let’s find out. Definition of Relative Atomic Mass (Ar) Okay let’s first go over the technical definition, the one you’ll see in textbooks and the one that examiners will probably want us to use. We’ll then break it down. “Relative atomic mass is the weighted … More Understanding Relative Atomic Mass: A Complete Guide

Tip for Remembering the Names of the Amino Acids

12th Jul 2026

The names of the 20 naturally occurring amino acids can be tricky to remember. A common tip is to create two mnemonics, one for essential amino acids (those we need to source from our diet) and one for non-essential amino acids (those that can be produced in the body under normal conditions). Here are the … More Tip for Remembering the Names of the Amino Acids

Moles of Ions in a Solution

22nd Jun 2022

In previous tutorials, we calculated the number of moles of a particular compound present in a reaction, including the number of moles of atoms present using the known number of atoms and Avogadro’s number. However, things can get a bit fiddlier when talking about ions. Contents: Examples of Salt Dissociation When a salt is placed … More Moles of Ions in a Solution

Gas Stoichiometry: The Ideal Gas Law

30th Jul 2020

The final tutorial in our series on gas stoichiometry will focus on an equation that combines different theories to comprehensively examine the properties of gases. However, we will soon see why this equation isn’t `ideal’ . … More Gas Stoichiometry: The Ideal Gas Law

Gas Stoichiometry: RTP

3rd Jul 2020

In the previous tutorial, we examined how to calculate the mass, amount and volume of a gas at standard temperature and pressure (STP). In this tutorial, we are going to calculate the same variables for gases in isolation and as part of a reaction – but at room temperature and pressure (RTP). … More Gas Stoichiometry: RTP

Gas Stoichiometry: STP

21st Jun 2020

When it comes to working out the mass, amount or volume of a gaseous substance in isolation or in a reaction, you have to consider the properties of temperature and pressure.

The first part of this tutorial on gas stoichiometry will focus on calculating the volume (in dm3 or litres), amount in moles and mass in grams of gaseous substances in isolation or within a reaction at standard temperature and pressure (STP). … More Gas Stoichiometry: STP

Percentage Yield and Atom Economy

7th Jun 2019

In this tutorial, we are going to go through how to calculate the percentage yield and the atom economy of a reaction. … More Percentage Yield and Atom Economy

Limiting and Excess Reactants

20th Apr 2019

In this first part of the third tutorial of the trio of tutorials on stoichiometry on this blog, we are going to be going through: what a limiting reactant is and how to identify one in a chemical reaction; how to calculate the amount of product produced using a certain amount of a limiting reactant and how to identify the excess reactant and work out how much excess is left over from a chemical reaction. … More Limiting and Excess Reactants

Determining the Number of Particles of a Reactant or a Product of a Chemical Reaction (with and without Conversion Factors)

21st Mar 2019

In this tutorial, we are going to be working out the number of particles – which could be atoms, molecules or formula units – of a substance that are acting as either a reactant or a product of a chemical reaction. … More Determining the Number of Particles of a Reactant or a Product of a Chemical Reaction (with and without Conversion Factors)