Answer:
207g
Explanation:
Given compound:
Ca(ClO₃)₂
The equivalent mass can be derived by summing the molar masses of each atom
Molar mass of Ca = 40
Cl = 35.5
O = 16
Now solve;
Molar mass = 40 + 2(35.5 + 3(16)) = 207g
Solution:
At the equivalence point, moles NaOH = moles benzoic acid
HA + NaOH ==> NaA + H2O where HA is benzoic acid
At the equivalence point, all the benzoic acid ==> sodium benzoate
A^- + H2O ==> HA + OH- (again, A^- is the benzoate anion and HA is the weak acid benzoic acid)
Kb for benzoate = 1x10^-14/4.5x10^-4 = 2.22x10^-11
Kb = 2.22x10^-11 = [HA][OH-][A^-] = (x)(x)/0.150
x^2 = 3.33x10^-12
x = 1.8x10^-6 = [OH-]
pOH = -log [OH-] = 5.74
pH = 14 - pOH = 8.26
