What are some interesting facts about chemistry?

 I will tell you a fact that is interesting plus extremely helpful in exams.

Fact: Most of the chemical compounds are white.

I made an analysis of the colour of chemical compounds which are popular and ionic. (I didn’t consider organic compounds because most of them are colourless and their colour isn’t asked in exams too).

And I made this graph:

The analysis was made as follows:

• Firstly, I made a list of precipitates which are analysed in qualitative analysis. A total of 125 compounds was listed.
  Then I categorized the compounds according to their colour:

• Out of the 125 compounds: 55 were white, 18 black, 20 yellow, 11 brown, 7 red, 7 green, 5 blue and 2 were pink.
  So if you choose a precipitate randomly there’s a probability of 44% that its colour is white.
• I made this graph for the probability of the colour of the chosen precipitate:

• Then, the compounds which are soluble in water were categorized. A total of 148 compounds was listed.
• Here’s how I made the colourwise distribution of the soluble chemical compounds:

• Out of the 148 compounds: 91 were white, 2 black, 12 yellow, 8 brown, 7 red, 9 green, 8 blue, 8 pink and 3 were violet.
  So if you choose a soluble compound randomly there’s a probability of 61.49% that its colour is white.

Here’s the graph for the probability of the colour of the chosen soluble compound:

• Then I collectively made a list of all the compounds (both soluble and insoluble) which were included above. A total of 273 compounds was listed.
• Out of the 273 compounds: 146 were white, 20 black, 32 yellow, 19 brown, 14 red, 16 green, 13 blue, 10 pink and 3 were violet.
  So if you choose a chemical compound randomly there’s a probability of 53.48% that its colour is white.

(Note that the colour included in the list of soluble compounds is of their anhydrous form. Some compounds change their colour when hydrated or dissolved in water).

• So finally, I came up with this graph:

• Now, If you are preparing for any exam, then you can use your photographic memory to learn the colour of compounds from the list that I made. As the font was given the colour which the compound has.
  
  Also, instead of learning the colour of all compounds, in particular, learn only non-white compounds because they are less in number.

What are some interesting facts about chemistry?

 

• A rubber tire is technically one single, giant, polymerized molecule.

• Lightning strikes provide the energy to "crack" O2 oxygen molecules into radicals which can reform into O3 (ozone). Hence the characteristic smell after lightning storms.
  
  
• More on O3 and rubber: ozone attacks the double bonds in elastomers such as tires and rubber tubing, in a process known as ozonolysis, which disrupts the neatly polymerized structure.
  
  

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  Only a tiny amount of ozone is needed to initiate the cracking. Eventually they take on this familiar appearance:

• Hydrofluoric acid HF is so violently corrosive it will dissolve virtually every earthly substance, with the exception of polyethylene or fluorocarbon plastic, lead or platinum. It is still classified as a "weak acid" - a source of confusion for many.

• The weight you lose as a result of working out is lost as CO2 and H2O vapor. Obvious in a way, but still impressive when you consider the sheer mass of that gas.

• The letter J does not appear in the periodic table.

• The frivolous use of helium in party balloons is building up towards a global shortage of the element, despite it being the second most abundant element in the universe. Helium is important in a number of industrial processes, and the shortage has sent helium prices sky high (pun intended). It is estimated that by 2020 there will be no more commercially available helium, at least for private individuals.
  
  [Source: http://www.telegraph.co.uk/science/9500575/Party-balloons-at-risk-as-helium-prices-go-up.html]

• Apples and pears release ethylene gas as they mature, which in turn can promote ripening in several other types of fruit. In other words it is not the best idea to store all your fruit together.
  
  
• Adding highly halogenated side groups increases the lipophilic character of a drug. Entirely counterintuitive (at least to me).
  
  

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• Copper(II) acetoarsenite, also known as Paris Green, was historically used in the Napoleonic era as a color pigment by painters, and on wallpapers. Come spring, the humidity in the air would allow molds to process the paint's arsenic atoms into arsine vapor AsH3, which is a deadly poison. As a result, a number of people fell ill or outright died around spring at the hands of their green wallpapers.
  

• Automotive airbags contain the supremely toxic salt sodium azide NaN3. In the event of a collision, a signal from the vehicle's deceleration sensors trigger an electrical impulse which raises the temperature around the salt dramatically, causing it to decompose into harmless nitrogen gas N2 which rapidly expands into the airbag.