Final Notes 15

Question 1

Requirement for volumetric analysis

Answer 1

Significant observable change
Complete (not irreversible)
Fast enough

Question 2

Test for HCl g

Answer 2

Place near conc NH3

Dense white fume

Question 3

Test for ClO-

Answer 3

Add a few drops HCl aq
Pale yellowish green gas
Moist blue litmus paper
Red and bleaches

Question 4

Completion indication

Answer 4

No more gas given out

All solid dissolved

Question 5

Separating funnel usage

Answer 5

Dissolve + shake
Collect org layer
Fractional distillation

Question 6

Filters

Answer 6

X filter x light passes

相反x absorbs x to a large extent

Question 7

Test for So2

Answer 7

Soaked filter paper
K2Cr2O7 to gas
Orange to green

Question 8

Test for SO4 2- vs SO3 2-

Answer 8

Ba(NO3)2/H+ with HNO3
White ppt SO4
No for SO3

Question 9

Rf value def

Answer 9

Ratio between migration distance of substance and solvent during chromatography

Question 10

Why different Rf values

Answer 10

Diff substance diff adsorptivity to stationary phase

Diff solubility to mobile phase

Question 11

Absorbance

Answer 11

High intensity high absorbance