MolSynapsequestion bank

MolSynapse / Question bank / Qualitative Analysis: Anions / Independent group: sulphate, phosphate, borate

JEE Advanced levelOne or more correct optionsDifficulty 3 of 3qa200

Each of the following solutions is treated with excess dilute $HCl$ and then $BaCl X_{2}$ solution. Which give a white precipitate that persists? (Solutions 2 and 3 were first treated with excess bromine water and the excess bromine removed.)

A $Na X_{3} PO X_{4}$ solution
B $Na X_{2} S X_{2} O X_{3}$ solution, pre-treated with excess bromine water
C $Na X_{2} SO X_{4}$ solution
D $Na X_{2} SO X_{3}$ solution, pre-treated with excess bromine water

Answer: B, C, D

Bromine water oxidises sulphite and thiosulphate to sulphate, which then gives insoluble

BaSO X_{4}

that stays in dilute

HCl

. Sulphate itself gives

BaSO X_{4}

. Phosphate gives

Ba X_{3} (PO X_{4}) X_{2}

, which dissolves in the dilute

HCl

, so no persistent precipitate forms.

Practice Qualitative Analysis: Anions More on Independent group: sulphate, phosphate, borate

Previous questionNext question

More questions on Independent group: sulphate, phosphate, borate

A borax sample is investigated. Which statements are correct? JEE Advanced level
Which statements regarding the independent group anions are correct? JEE Advanced level
Which of the following are correct for boron compounds met in the borate test? JEE Advanced level
Assertion (A): The green flame test for borate is performed with ethanol (or methanol) and conc. H2SO4, not with dilute acid. Reason (R): Fo... JEE Advanced level
A solution contains 0.0100 mol Na2SO4 and 0.0100 mol Na3PO4. Excess BaCl2 is added at neutral pH, forming both barium salts completely, and ... JEE Advanced level
A solution of Na2HPO4 in excess is treated with 0.030 mol of AgNO3, forming yellow Ag3PO4 completely according to 3Ag+ + HPO4^2- -> Ag3PO4 +... JEE Advanced level