Mole ConceptMedium
Question
Calculate the milimoles of SeO32- in solution on the basis of following data :
70ml of
solution of KBrO3 was back titated with 12.5 mL of
solution of 2 NaAsO2
The reaction are given below.
I. SeO32- + BrO3- + H+ → SeO42-Br2 + H2O
II. BrO3- + AsO2- + H2O → Br- + AsO43- + H+
70ml of
solution of KBrO3 was back titated with 12.5 mL of
solution of 2 NaAsO2The reaction are given below.
I. SeO32- + BrO3- + H+ → SeO42-Br2 + H2O
II. BrO3- + AsO2- + H2O → Br- + AsO43- + H+
Options
A.1.6 × 10-3
B.1.25
C.2.5 × 10-3
D.None of these
Solution
(I) 
(II)
In reaction (II)
gm.eq. of BrO3- = gm.eq.of AsO2-
nBrO3- × 6 = nAsO2- × 2
=
× 2 = 10-3
nBrO3- =
In reaction (I)
moles of BrO3- consumed
= 10-3
gm eq. of SeO32- = gm. eq. of BrO3-
nSeO32- × 2 = 10-3 × 5;
nSeO32- = 2.5 × 10-3

(II)

In reaction (II)
gm.eq. of BrO3- = gm.eq.of AsO2-
nBrO3- × 6 = nAsO2- × 2
=
× 2 = 10-3nBrO3- =

In reaction (I)
moles of BrO3- consumed
= 10-3gm eq. of SeO32- = gm. eq. of BrO3-
nSeO32- × 2 = 10-3 × 5;
nSeO32- = 2.5 × 10-3
Create a free account to view solution
View Solution FreeMore Mole Concept Questions
The molarity of a solution obtained by mixing750 mL of 0.5(M) HCl with 250 mL of 2(M) HCl will be :-...In the following reaction 3A + B ⇋ 2C + D Initial mole of B is double of A. At equilibrium mole of A and C are equ...How many litres of detonating gas may be produced at 0o C and 1 atm from the decomposition of 0.1 mole of water by an el...A gaseous alkane is exploded with oxygen. The volume of O2 for complete combustion to the volume of CO2 formed is in 7:4...The equivalent weight of MnSO4 is half its molecular weight when it is converted to :...