I honestly have no clue on this one
The given question is incomplete. The complete question is :
What volume of 0.160 M solution of KOH must be added to 550.0 mL of the acidic solution to completely neutralize all of the 0.150 M hydrochloric acid?
Answer: Volume in liters to three significant figures is 0.516 L
Explanation:
To calculate the volume of acid, we use the equation given by neutralization reaction:

where,
are the n-factor, molarity and volume of acid which is 
are the n-factor, molarity and volume of base which is KOH
We are given:

Putting values in above equation, we get:
(1L=1000ml)
Thus volume in liters to three significant figures is 0.516 L
Mercury(II) oxide, a red solid, decomposes when heated to produce mercury and oxygen gas. Mercury(II) oxide is a red solid. When it is heated, it decomposes into mercury metal and oxygen gas. A reaction is also considered to be a decomposition reaction even when one or more of the products are still compounds.