An organic acid on cooling below 16.5°C crystallises out in the pure form, forming a crystalline mass resembling ice. Draw the structural diagram of this carboxylic acid.

Magnesium ribbon is added to dilute HCl. A gas is liberated along with the formation of a compound. Draw an electron dot diagram to show the structure of the compound that is formed.

Calcium hydroxide dissolves in water and forms a ion and a negative ion. Draw the structure of the negative ion.

Draw the structure of the following organic compounds:
2–methyl butane