GROUP II ANIONS

Question 1

Group II Anions contains only

Answer 1

chromate and sulfate ions.

Question 2

Group II Anions are precipitated by the group reagent

Answer 2

Ba(Ac)2 - Barium Acetate

Question 3

They are precipitated as _________ and ___________ in slightly basic solution.

Answer 3

BaCrO4 and BaSO4

Question 4

BasO4 is separated from BaCrO4 by its Solubility in

Answer 4

3M HCl

Question 5

The chromate ion is confirmed by reprecipitating BaCrO4 from the _________ of the acid solution

Answer 5

centrifugate

Question 6

Maximum drops of Ba(Ac)2

Answer 6

15

Question 7

Precipitate may be composed of

Answer 7

BaSO4 and BaCrO4

Question 8

RESIDUE may be

Answer 8

BaSO4

Question 9

PRECIPITATE may be

Answer 9

BaCrO4

Question 10

Precipitating agent of SULFATE ION

Answer 10

3M HCl

Question 11

Color that confirms the presence of SULFATE IONS

Answer 11

White

Question 12

Precipitating agent of CHROMATE IONS

Answer 12

2.5 F sodium acetate - NaOAc

Question 13

Color that indicates the presence of CHROMATE IONS

Answer 13

Yellow

Question 14

Precipitating agent of Group II

Answer 14

Ba(Ac)2 - Barium Acetate

Question 15

Group II ions are precipitated with _________ in slightly basic solution.

Answer 15

Barium Acetate

Question 16

What are the group II precipitates

Answer 16

BaSO4
BaCrO4

Question 17

The analysis of this group involves no difficulties because the presence of chromate ions shows _______ color.

Answer 17

yellow

Question 18

Addition of ____ dissolves BaCrO4

Answer 18

HCI

Question 19

After adding HCl, _____ is the precipitate and ______ is the centrifugate

Answer 19

BaSO4 ~ BaCrO4

Question 20

Initial detection of Sulfate Ions

Answer 20

White precipitate in the precipitation of Ba(Ac)2

Question 21

How is the he presence of sulfate confirmed?

Answer 21

Addition of more HCI (but not too much, as acid can shift equilibrium to the left, dissolving more barium sulphate) dissolves more BaCrO4. Thus if precipitate will not dissolve, which is BaSO4, sulphate is present.

Question 22

How is the presence of Chromate ions confirmed?

Answer 22

The addition of sodium acetate to the acidic chromic solution lowers the Hydrogen ion concentration sufficiently to permit reprecipitation of BaCrO4, the yellow precipitate.