Question

0.1176g of a weak acid (molar mass=98) required 15ml of 0.24 NaOH to reach equivalence point find the basicity

Answer 1

Moles of NaOH = 15/1000  x 0.24 = 0.0036

Moles of acid = 0.1176/98 = 0.0012

Mole ratio

Acid : NaOH = 0.0012/0.0012 : 0.0036/0.0012
 
                    = 1 : 3

∴ The basicity of the acid = 3

Answer 2

First of all we have to find out number of moles of acid as well as base .
we know, Number of mole = Given Weight/molecule weight
Here given weight of acid = 0.1176g
and molecular weight = 98 g/mol
Now, number of mole of acid = 0.1176/98 = 0.0012

molarity of base = 0.24M , volume of base = 15mL = 0.015L
so, molarity of base = number of mole of base /volume of solution in Litre
0.24M= number of moles of base/0.015 L
number of moles of base = 0.0036

Means, 0.0012 mol of a weak acid and 0.0036 mol of strong base (NaOH) neutralize to reach equivalent point.
∴ 1 mol of weak acid and 3 mol of NaOH neutralize to reach equivalent point.
Hence, there are three Hydrogen atoms is replaceable by NaOH in given weak acid .
Hence, basicity = 3.