When amino acids are linked together, they form a peptide bond. When it joins two amino acids, it forms a dipeptide bond. When a long chain of amino acids are joined by peptide bonds, it becomes a protein. As shown in the picture, it loses H-OH molecules.
So, it will appear in the product side as a H₂O molecule.
Then I would guess the answer is D because Na2OH is much more common and stable than Na2O is <span />
Explanation:
Nitric acid reacts with copper according to the reaction: ... 4 HNO3(l) + Cu(s) ==> Cu(NO3)2(s and aq) + 2 NO2(g) + 2 H2O(l) The copper nitrate salt that forms is a deep blue color. The nitrogen dioxide is a maroon vapor.
3 answer for number 3.4 is the answer for number 4