Is there any answers to choose from?
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The reaction for burning of charcoal or complete combustion is as follows:

From the above balanced reaction, 1 mole of carbon releases 1 mole of
gas.
Converting mass of charcoal into moles as follows:

Molar mass of pure carbon is 12 g/mol thus,

The same moles of
is released. Converting these moles into mass as follows:
m=n×M
Molar mass of
is 44 g/mol thus,

Converting mass into kg,

Thus, total mass of gas released is 5.5 kg.
NH3 + H2O -> NH4+ + OH- is the answer I think I just did this in class today
Answer:
the unknown substance is a protein
Explanation:
The biuret test is one of the tests for proteins. It can be used to detect peptide linkages. The biuret test is carried out in an alkaline solution. A coordination complex is formed leading to the appearance of a violet color.
Summarily, the biuret method is a colorimetric technique used to test for proteins and peptides. It involves the formation of a purple (violet) complex of Copper salts in alkaline solution.
Hence when the biuret reagent is added to an unknown substance and it turns purple, the unknown substance is a protein
When an atom combines chemically with another atom, it either gains, loses, or shares ELECTRONS.