Answer:
The answer to your question is: A. NaOH
Explanation:
Data
mass = 2.5g of unknown base
volume = 289 ml = 0.289 l
concentration = 0.216 M
What is the base= ?
Formula
Molarity (M) = # moles / Volumen (V)
# moles = M x V
Process
# moles = 0.216 x 0.289 = 0.062 in the solution
MW NaOH = 23 + 16 + 1 = 40 g
MW LiOH = 7 + 16 + 1 = 24 g
MW KOH = 39 + 16 + 1 = 56 g
Rule of three
40 g of NaOH ------------------- 1 mol
2.5 g -------------------- x
x = 2.5 x 1 /40 = 0.062 moles is the same amount of moles in the
solution is the answer
24 g of LiOH ----------------- 1 mol
2.5 g --------------------- x
x = 2.5 x 1 / 24 = 0.104 moles
56 g of KOH ------------------ 1 mol
2.5 g -------------------- x
x = 2.5 x 1 / 56 = 0.045
