Chemistry, art and history collide in the latest edition of Periodic Graphics in C&EN. The graphic examines pigments with links to the death of Napoleon, blue poo and cow urine. Read the full graphic on the C&EN site.
Along with universal indicator, litmus paper is one of the most commonly encountered pH indicators in school chemistry lessons. Unlike the range of colours produced by the former, litmus is pink-red in acidic solutions and blue in alkaline solutions. This graphic highlights its complex origins in lichens and the chemical changes that account for its colour change.
Decades of marketing have placed diamonds on a pedestal above other gemstones. They’re an engagement ring tradition and are also found in lots of other jewellery. However, there’s another, coloured gemstone which is arguably superior. Not content with being one colour, it can display a whole range of hues, depending on the light falling on it. The gemstone in question? Alexandrite.
We all know examples of everyday substances that can be classified as acids or alkalis: lemon juice is acidic, bleach is alkaline, and so on. Another substance that can be found in your kitchen can be used to test other substances to determine whether they are acidic or alkaline. The chemicals that give red cabbage its colour also allow it to be used as a pH indicator – this post looks at how!
With Easter just around the corner, this month’s edition of Periodic Graphics in C&EN takes a look at the chemistry behind the Easter tradition of dyeing eggshells different colours. Click to view the full graphic on the C&EN site!
A particular bodily fluid featured in the political news earlier this week, which got me thinking about the chemical causes behind the colours of the waste products we expel from our bodies. What makes urine golden, faeces brown, and bile green? The answers to all of these questions have a common chemical link.