Write the chemical reactions associated with the ‘borax bead test’ of cobalt (II) oxide.
Answers
CoO + B2O3 -HEAT-> Co(BO2)2
Answer:
Explanation:
The borax bead test represents the creation of a glassy bead that variously changes colours when put under a Bunsen flame. It potentially reveals a whole series of compounds, depending on their chemical features.
Borax is referred to as the compound with formula Na2B4O7 • 10H2O,and the IUPAC name as sodium tetraborate decahydrate. To create the bead, platinum is commonly used wire that is firmly attached to the end of a glass stick. Before creating the pearl, the wire is cleaned and moistened with 6N HCl,
The first reaction is the popcorn effect, also known as the swelling of the substance caused by the loss of crystallization water:
Na2B4O7 • 10H2O Na2B4O7 + 10H2O ↑
For further warming, tetraborate decomposes to give sodium metaborate and the boric oxide.
Na2B4O7 2NaBO2 + B2O3
Thus, this is the pearl before the reaction with the unknown substance, that should appear clear and colorless.