In order to get HgO you would need 2Hg+1O2=2HgO. Since oxygen is diatomic you need two when it stands alone causing you to need two mercuries to balance out the reactants and the product I hope this helps
Answer:
a. The phenolphthalein acts as a color changing indicator to signal the endpoint of the reaction.
Explanation:
Phenolphthalein is an organic substance with chemical formula
.
It is a substance commonly used in acid-base titrations to indicate the end point in the titration because phenolphthalein is colorless in acidic solutions but turns a purplish-pink color in basic solutions.
In this way it helps visually to notice when the final point of the titration has been reached.
Explanation:
a.
→ ?




Removing common ions from both sides, we get the net ionic equation:

b.
→

No precipitation is occuring.
c.
→




Removing common ions from both sides, we get the net ionic equation:

d.
→




Removing common ions from both sides, we get the net ionic equation:

-NH2 is the most favorable for the reaction