Well really the right thing to do is find the nearest shower and rinse them off so I believe C. would be the best answer
Answer: 118.5 grams
Explanation:
Molarity is defined as the number of moles of solute dissolved per liter of the solution.
where,
n= moles of solute
= volume of solution in ml = 500 ml
moles = 0.75
moles of solute =
0.75 =
mass of 
= 118.5 grams
Thus mass of needed to prepare 500 mL of this solution iis 118.5 grams
A) Initial moles of NH3 = 75/1000 x 0.200 = 0.015 mol
Moles of HNO3 added = 28/1000 x 0.500 = 0.014 mol
NH3 + HNO3 => NH4+ + NO3-
Moles of NH3 left = 0.015 - 0.014 = 0.001 mol
Moles of NH4+ = 0.014 mol
Ka(NH4+) = Kw/Kb(NH3)
= 10-14/1.8 x 10-5 = 5.556 x 10-10
Henderson-Hasselbalch equation:
pH = pKa + log([NH3]/[NH4+])
= -log Ka + log(moles of NH3/moles of NH4+) since volume is the same for both
= -log(5.556 x 10-10) + log(0.0065/0.014)
= 8.14
