Answer:
The mass of O₂ that will be needed to burn 36.1 g B₂H₆ is 125.29 g.
Unfortunately, you haven't shared any data list which would make braunly users able to help you. The only thing I can suggest you is to write the neutralization reactions, this can make you understand the calculations more or less clearly. Please, next time check your attachments carefully.
Mg₃N₂ + 6H₂O = 3Mg(OH)₂ + 2NH₃
The equivalency point is at the point of the titration where the amount of titrant added neutralize the solution. When it’s a strong acid strong base titration, the equivalence point will be 7. When it is a weak acid strong base, the equivalence point it more basic (the exact number depends on what acid and base you use). And when it is a strong acid weak base, the equivalence number is more acid (the exact number depends on what acid and base you use). Hope this helps!