3B Analatical Chemistry

Question 1

2 types of study in analatical chemistry

Answer 1

Qualitative and Quantitative

Question 2

Qualitative analysis includes

Answer 2

Identification of an unknown substance by chemical tests.

Question 3

Chemical tests include the use of

Answer 3

1. Sodium and Ammonium Hydroxides on salt solution.

2. Observation of color and solubility of the precipitates formed.

Question 4

A salt is colored if

Answer 4

Its cation or anion is colored.

Question 5

Salts of elements in group ______ are colorless

Answer 5

1,2 and 13 to 17 are colorless.

Question 6

Salts of elements in group ______ are colored

Answer 6

3 to 12

Question 7

Name the color of the following elements:

1. Cu2+
2. Cr3+
3. Mn2+
4. Fe2+
5. Fe3+
6. Co2+
7. Ni2+

Answer 7

1. Blue
2. Green
3. Pink
4. Green
5. Brown or yellow
6. Blue or pink
7. Green

Question 8

Cr2O7

MnO4

Answer 8

Orange

Pink/Purple

Question 9

Calcium with NaOH

Answer 9

White insoluble

Question 10

Magnesium with NaOH

Answer 10

Dull white insoluble

Question 11

Iron (II) with NaOH

Answer 11

Dirty green Insoluble

Question 12

Iron (III) with NaOH

Answer 12

Reddish brown insoluble

Question 13

Cu2+ with NaOH

Answer 13

Pale blue Insoluble

Question 14

Zn with NaOH

Answer 14

Gelatinous white soluble

Question 15

Zn(OH)2 Can further react with ______ to form ______.

Answer 15

NaOH, Na2ZnO2

Question 16

Pb(NO3)2 Can further react with _______ to form _______.

Answer 16

NaOH, Na2PbO2.

Question 17

Both sodium zincate and Sodium plumbite gives a

Answer 17

Colorless soltion

Question 18

Ca with NH4(OH)

Answer 18

Cant form a precipitate

Question 19

Why does Ca not react with NH4(OH)

Answer 19

Concentration of OH- ions is low.

Question 20

Mg with NH4(OH)

Answer 20

Dull white Insoluble

Question 21

Fe2+ with NH4(OH)

Answer 21

Dirty green insoluble

Question 22

Fe3+ with NH4(OH)

Answer 22

Reddish brown Insoluble

Question 23

Cu2+ with NH4(OH)

Answer 23

Pale blue soluble

Question 24

Cu(OH)2 can further react with ______- to give _____ and ______.
It can react with ______ and ______- to give ________ and ________.
(NH4OH)

Answer 24

NH4OH, [Cu(NH3)4] (OH) 2 -> Tetramine copper hydroxide.

NH4OH, (NH4)2SO4, [Cu(NH3)4] (SO4) -> Tetra amine copper sulphate.

Question 25

Tetra amine copper (sulphate and hydroxide) gives a

Answer 25

Inky blue for suplhate only and Deep blue solution for both.

Question 26

Zn with NH4(OH)

Answer 26

White gelatinous soluble/dirty white

Question 27

Zn(OH)2 can further react with ______- to give _____ and ______.
It can react with ______ and ______- to give ________ and ________.
(NH4OH)

Answer 27

NH4OH, [Zn(NH3)4] (OH) 2 -> Tetramine Zinc hydroxide.

NH4OH, (NH4)2SO4, [Zn(NH3)4] (SO4) -> Tetra amine Zinc sulphate.

Question 28

Tetra amine Zinc (sulphate and hydroxide) gives a

Answer 28

Colorless

Question 29

In both the “further” reactions of Zn and Cu, what should be in excess?

Answer 29

NH4(OH)

Question 30

Lead with NH4(OH)

Answer 30

Chalky white insoluble

Question 31

Zn + NaOH

Answer 31

Na2ZnO2 + H2

Question 32

Which metal requires water to from “-ate”

Answer 32

Aluminium only.

Question 33

Metals + hot conc. caustic alkalis ->

Answer 33

Soluble salt + Hydrogen

Question 34

____ and ____ of _____, ___ and _______ are amphoteric.

Answer 34

Hydroxides; Oxides; Zn, Al and Pb

Question 35

Amphoteric oxides reacts with ___ alkalis

Answer 35

Hot and Concentrated

Question 36

This -ate, doesnt have any prefeix always.

Answer 36

Aluminium only; Others have “2” as the subscript