11)
Balanced chemical equation is:
3 NaOH + H3A ---> NaA + 3 H2O
lets calculate the mol of NaOH
volume , V = 25.08 mL
= 2.508*10^-2 L
use:
number of mol,
n = Molarity * Volume
= 0.142*2.508*10^-2
= 3.561*10^-3 mol
According to balanced equation
mol of H3A reacted = (1/3)* moles of NaOH
= (1/3)*3.561*10^-3
= 1.187*10^-3 mol
This is number of moles of H3A
mass(H3A)= 0.251 g
use:
number of mol = mass / molar mass
1.187*10^-3 mol = (0.251 g)/molar mass
molar mass = 2.114*10^2 g/mol
Answer: 211 g/mol
Only 1 question at a time please
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