I think it’s c but I could be wrong
        
             
        
        
        
One difficulty encountered in precipitation titration is that it is hard to determine the exact end point of its reaction.
Precipitation titration is a titration in which a  reaction  occurs from the  analyte and titrant  to form an insoluble precipitate.
With the use of silver for the titrations, (argentometric) we are able to develop many precipitation reactions.  
 The  precipitation titrimetry  methods with the use of argentometry includes  
• Mohr’s Method
• Fajan’s Method
• Volhard’s Method
Difficulties encountered in precipitation titration includes
- Getting the exact end point is hard.
- it is a very slow titration method.
- it includes periods of filtration and cooling thereby reducing the reactions available for this type of titration.
See more on Precipitation: brainly.com/question/20628792
 
        
             
        
        
        
Answer:
107.8
Explanation:
64 gram of N2H4 produce 72 gram of H20
then by crossmultiplication
64*121.3/72=107.82
 
        
             
        
        
        
Virtually all acids release hydrogen ions (or protons) in the water