Nevo Mantel
França
10B
Chemistry
Lab
report: Types of chemical reaction
Element
|
Before
|
During
|
After
|
Methane
|
Transparent gas, passing through the tube.
|
The sparks suddenly make the fire turn on and
after turning it on, and after turning it on we regulate the
oxygen making the fire blue or yellowish orange.
|
After regulating with no oxygen the methane or
the fire gets blue.
|
Methane
Iron
|
Transparent gas,
passing through the tube.
A ball of steel wool, where it is squished and
shiny light gray.
|
There were little sparks occuring during the
burning of the steel wool and it didn’t get on fire.
|
The steel wool doesn’t get on fire only
reacts and turns the same.
|
Methane
Copper (II) Carbonate
|
Transparent gas,
passing through the tube.
Has a greyish green color, powder with really
crumbled particles, also really smooth.
|
Some seconds pass and the greyish green powder
gets black, really dark black powder.
|
After getting the match lit and putting it on
top of the test tube the fire goes out because of carbon dioxide
released.
|
Station 1 Observation Table – by, Nevo Mantel
Station 2
Observation Table –
Element
|
Before
|
During
|
After
|
Lead (II) Nitrate
Potassium Iodide
|
Transparent
liquid, really like water, can see through, has no color.
Looks really like lead nitrate and water also
is colorless, and transparent.
|
Exactly when put together the chemicals got
both really dark, non-transparent yellow.
|
After some minutes the solid dark yellow goes
down and the yellow foggy liquid goes up.
|
Copper Sulfate
Iron
|
Blue transparent
liquid, looks like pool water.
A ball of steel wool, where it is squished and
shiny light gray.
|
When put in the steel wool gets from shiny grey
to dark brown and red or maroon, the iron had its color change
completely.
|
The liquid gets transparent and the wool stays
redish dark looking like copper.
|
Baking Soda
Vinegar
|
White big grains
of baking soda.
Transparent and really light yellow liquid.
|
It suddenly starts bubbling and fast goes until
the middle of the test tube.
|
After it separates into yellowish liquid and
white grains at the bottom.
|
Station 3
Observation Table –
Element
|
Before
|
During
|
After
|
Potassium
Barium
|
Yellow liquid and
also transparent you can see through it, looks like pee, when you
don’t drink water.
Transparent liquid, looks really like water
|
The barium was poured in the test tube and it
got white liquid until it “combined with potassium making dark
and non-transparent particles, because of double displacement;
after sometime it becomes a light yellow solid.
|
Separate into liquid and solid, yellow
transparent liquid on top and light yellow solid on bottom, making
a suspension.
|
Potassium
Silver Nitrate
|
Yellow liquid and
also transparent you can see through it, looks like pee, when you
don’t drink water.
Less transparent, also looks like water but is
not as transparent.
|
Suddenly the chemicals reacted transforming the
color from yellow and transparent to sudden red tomato color.
|
After 10 minutes the yellow liquid goes up and
the solid red color stays on the bottom.
|
Barium
Silver Nitrate
|
Transparent
liquid, looks really like water
Less transparent, also looks like water but is
not as transparent.
|
Got suddenly foggy and you can’t see through
it after the reaction.
|
After sometime the light pink solid goes down
and the transparent liquid goes up.
|
Station 4
Observation Table –
Element
|
Before
|
During
|
After
|
Hydrochloric Acid
Sodium Hydroxide
|
Transparent
liquid, looking like water.
Looks like the acid and also if transparent and
colorless.
|
It turns really dark pink and can be seen
through. After, there is more chemical poured in so the pink gets
more intense and the beaker gets warm in the bottom.
|
It continues pink and since there is poured a
big amount of chemical making it get intense pink.
|
Observation/Results
table, by França
Reaction
|
Before
|
During
|
After
|
a)
Burning methane
|
The
gas was colorless, no smell, invisible
|
The
flame was blue, it was very stable, didn’t move, the blue was
very intense but not dark.
|
There
was nothing left
|
b)
Oxidation of Iron (steel wood)
|
Regular
steel wood, gray, rough.
|
When
placed on the fire, many sparks appeared but the steel wood didn’t
get in fire
|
The
steel wood got darker and momentarily hot.
|
c)Thermal
decomposition of Copper (II) Carbonate
|
Dark
blue/green, smooth, very small crystals
|
The
powder got together and black, the process of getting together was
similar of the production of “tapioca”, after putting the
lighted match on the test tube, it turned off.
|
The
substance got black and together.
|
j)
Hydrochloric acid and Sodium Hydroxide
|
Both
base and acid were smell less and colorless.
|
The
mixture of HCL with 2 drops of phenolphthalein was still the same,
with several drops of NaOH it got totally pink
|
It
kept pink but if one drop of any element was placed on the beaker
if would get colorless again
|
d)
Lead (II) Nitrate and Potassium Iodide
|
Both
liquids a weak smell and colorless
|
After
mixing the liquids, it became a yellow liquid. 10 minutes to
happen
|
Precipitated
matter and the liquid was clearer. It was like a suspension
|
e)Copper
sulfate and Iron
|
The
liquid was blue and had no smell
|
The
steel wood, stated floating and gradually was going down, it was
getting red as rust.
|
The
liquid got white and the ball spread.
|
f)
Vinegar (acetic acid) and baking soda (sodium bicarbonate)
|
Vinegar’s
smell and the sodium bicarbonate was normal
|
An
“explosion” happened as school volcanoes, it was quick and
strong
|
Only
liquid with vinegar’s smell
|
g)
Barium chloride and K2CrO4
|
Potassium
chromate was yellow. Barium chloride colorless
|
Small
“explosion”, it got a darker yellow.
|
Precipitated
matter
|
Reaction
|
Before
|
During
|
After
|
h)
Potassium chromate and silver nitrate
|
K2CrO4
= yellow Silver nitrate = white
|
At
the first time when the liquids got in touch, it got a red tomato.
|
Reddish/yellow,
precipitated matter.
|
i)
Barium Chloride and Silver nitrate
|
both
liquid were white
|
Instant
reaction, appearance like milk, opaque
|
Precipitated
matter, total separation
|
Discussion
Burning methane:
CH4 (g)
+ O2 (g)
→ 2H2O
(g) + CO2 (g)
Combustion
Oxidation of Iron:
2Fe (III) (s) + 3O2 (g)
→ Fe2(O2)3
(s)
Synthesis
Thermal
decomposition of Copper (II) Carbonate: CuCO3(S)
→ CuO(s) + CO2(g)
Decomposition
Lead (II) Nitrate
and Potassium Iodide: Pb(NO3)2
(l) + 2KI(l) → PbI2
(l) + 2KNO3
(l)
Double Displacement
Copper Sulfate and
Iron: Cu2SO4 (l)
+ Fe(II) → FeSO4(l)
+ 2Cu(s) Single Displacement
Vinegar and baking
soda: CH3COOH(l)
+ NaHCO3(s)
→ C2H3O3(l)
+ H2CO3
(l)
Double Displacement
Barium Chloride and
Potassium Chromate: BaCl2(l)
+ K2CrO4(l)
→ BaCrO4(l)
+ 2KCl(s) Double Displacement
Potassium Chromate
and Silver Nitrate: K2CrO4(l)
+ 2AgNO3(l)
→ 2KNO3(s)
+ Ag2CrO4(l)
Double Displacement
Barium Chloride and
Silver Nitrate: BaCl2 (l)
+ 2AgNO3 (l)
→ Ba(NO3)2
(l) + 2AgCl (l) Double
Displacement
Hydrochloric acid
and Sodium Hydroxide: HCl (aq.) +
NaOH(aq.) → NaCl(s) + H2O(l)
Neutralization
1)
Chemical reactions in generally always give indicators of when the
reaction is happening and if it’s actually a chemical reaction and
not a physical change, such changes can be production of smoke,
change of color, heat, production of bobbles and many other features.
At reaction “A”, the fire was the indicator of the chemical
reaction, since it produced heat. On reaction “B” the indicators
were the production of sparks and how the steel wood got darker. On
reaction “C” the indicator was change of color, the matter
getting together and a very small production of smoke. At reaction
“D” the indicator was the change of color. Reaction’s “E”
indicator was the change of color and that the steel wood started on
the top of the liquid, and by the end of the reaction it went to the
bottom. Reaction’s “F” indicator was the production of bobbles
instantly, as a small explosion. At reaction “G” was the
explosion followed by a change of color of the liquid. On reaction
“H” the indicator was the change of color to red. At reaction “I”
the change of color was also the indicator. On reaction “J” the
change was the color, but, if the 2 drops of phenolphthalein were not
placed on the beaker, the change would not be able to be seen at
naked eye.
2)
Synthesis is when 2 elements react and produce one compound,
which has molecules from both elements, an example of that was the
Oxidation of Iron (reaction “B”). Decomposition is when a
compound which is made usually by two elements –can be more than 2
– get separated and gives the 2 elements by themselves, example of
that is thermal decomposition of Copper Carbonate. Single
displacement is when a compound made up by two elements –
usually – and to it, is add one element, at the reaction, the one
of the ions will get alone and the element which was originally by
itself will get together to form a new compound and have a new
element by itself, as example of this reaction we have Copper Sulfate
and Iron. Double displacement is when 2 compounds made by two
elements change their elements, if the compound number 1 is AB and
the compound number 2 is CD (A and C are positive ions and B and D
are negative) they will get in a different order, so, after the
reaction takes place the new compounds will be AD and CB, example of
that is Barium Chloride and Potassium Chromate. Neutralization
works the same way as Double displacement, in fact, they are almost
the same, although, the function of neutralization is to have and
acid and a base and get a new solution with the PH of 7, which means
that is neutral, as water, example of that is Hydrochloric acid and
Sodium Hydroxide.
3)
The reactants which were gases were: Methane (CH4)
and Oxygen (O2).
Solid: Steel wood (Fe), Cooper Carbonate (CuCO3)
and the bake soda or sodium bicarbonate (NaHCO3).
The aqueous compounds were Hydrochloric acid (HCL) and Sodium
Hydroxide (NaOH). All the other reactants were liquids: Lead Nitrate,
Potassium Iodide, Copper Sulfate, Acetic Acid (vinegar), Barium
Chloride, Potassium Chromate and Silver Nitrate.
4)
Two aqueous solutions can obtain solid precipitated matter when
neutralization takes place, as it happened of the reaction of
Hydrochloric acid and Sodium Hydroxide, when the product of this
chemical reaction gives a salt and water, which was the exact same
thing that this reaction gave. HCl (aq.) + NaOH → NaCl + H2O,
by looking on the chemical formula of the reaction it’s possible to
affirm that what was synthetized after the reaction was salt (NaCl)
and water, since a neutralization occurred, which is in charge of
making the product have a PH of 7.
5)
H3O(aq.)
+
Cl(aq.) →
H2O
+ HCl. Those reactions are different from the neutralization that was
done on the lab, because this reaction does not give precipitated, it
gives water and another acid and the reaction on the lab produced
water and salt.
6)
Since the final product was water and salt (H2O
+ NaCl),
according to the logic it would be produced after the reaction pure
salt, since the water would have gone, but, since it was add
phenolphthalein
to the solution I can’t predict if this would make any difference
when boiling the new solution produced from the Hydrochloric acid and
the Sodium Hydroxide.
7)
On the last experiment when Hydrochloric
acid and the Sodium Hydroxide were put together, the phenolphthalein
was used to see when the neutralization would be complete, which
means, when the PH of the solution were 7. “Appearance: White
to pale yellow crystals. Odor: Odorless. Solubility: Slightly
soluble in water. Density: 1.299 pH: No
information found. %
Volatiles by volume @ 21C (70F): No
information found. Boiling
Point: Not
applicable. Melting
Point: 258
- 262C (496 - 504F) Vapor
Density (Air=1): No
information found. Vapor
Pressure (mm Hg): No
information found. Evaporation
Rate (BuAc=1): No
information found.”
(Fragment
directly quoted from source number 2). When
in contact with acid solution, the substance is colorless and pinkish
in basic solution. The formula of phenolphthalein
is C20H14O4,
and
works of the following way, phenolphthalein
starts to change color at the point when the moles of acid equal the
moles of base. Although this color change occurs at a pH of 8.0 and
not at a pH of 7.0 phenolphthalein is commonly used because of the
distinctive color change that occurs.
Sources
"Chemistry
and Society." Chemical
Reactions (2008):
105. Web. 2 Apr 2011.
<
Baker,
Mallinckrodt. "PHENOLPHTHALEIN." (2007): 2015. Web. 2 Apr
2011. <
Wikipedia
Dice,
David. "Phenolphthalein ." (1998): n. pag. Web. 2 Apr 2011.
<