Experiment 5

ChemLab

popping sound

. Water (in a beaker) + Na, Reaction?

yellow

Added with methyl orange, what is the color?

pinkl

Added with phenolphthalein

black particles

Mg    +   CuSO4      è    Mg SO4      +   Cu

red particles

Mg    +   FeCl3      è    MgCl 2       +   Fe

black partciles

Zn    +   CuSO4      è     ZnSO 4      +  Cu

gray particles

Mg    +   ZnCl2        è     MgCl 2       +   Zn

red particles

•Zn    +   FeCl3        è     ZnCl 2        +   Fe

 

reddish brown particles

Fe    +  CuSO4      è     FeSO 4    +   Cu

\

Fe2O3•xH2O –

What is the chemical equation of hydrated iron(III) oxide?

agar agar

used as a catalyst to make corrosion faster

Phenolphthalein

turns pink in the region where oxygen is taking electrons producing OH – .

Potassium hexacyanoferrate 

used to detect the presence of Fe 2+ forms a blue or green or blue green color in the region where oxidation of iron is taking place (where iron is losing electrons)

K3Fe(CN)6

Chemical equation of Potassium hexacyanoferrate ?

Fe3\[Fe(CN)6\]2

Chemical equation of Prussian blue

Prussian blue

reacts   with Fe2+ ions to form a dark blue mixed iron(II)/iron(III) compound and commonly known as

less corrosion

agar-agar solution + K3Fe(CN)6 +  phenolphthalein  +  Fe nail

Straight Nail

corrosion will occur rapidly

Solutions: agar-agar solution + K3Fe(CN)6 + phenolphthalein + bent Fe nail

\

less corrosion occur

Solutions: agar-agar solution + K3Fe(CN)6  +   phenolphthalein  + Fe nail coated with mossy Zn

iron nail rusts quickly

Solutions: agar-agar solution + K3Fe(CN)6  +   phenolphthalein  + Fe nail wrapped with copper wire

K, Na, Ca, Mg, Al and Zn.

The rate of rusting of iron __decreases__ if the iron (Fe) in contact with any of these metals, what are those?

Sn, Pb, Cu, Hg, Ag and Au.

The rate of rusting of iron __increases__ if the iron (Fe) in contact with any of these metals, give the following.