Reaction Prediction Lab
Group 6
Introduction
Like meteorologists predict the weather, chemists predict the products of
reactions. The types of reactions that can be predicted by chemists are combustion,
combination, decomposition, single replacement, and double replacement, (brief
description of each type) whereas meteorologists predict storms and types of fronts. If the
reactants are known within the experiment, then the reaction can be determined by the
students in class.
Materials and Methods
First, for lab 1, the Bunsen burner was lit so that two cones appeared. Then
magnesium was obtained and held over the flame of the Bunsen burner and it burned a
very bright white light for a few seconds, and turned to ash. Next, copper was obtained
and it was held over the flame and it glowed orange. The flame above the copper wire
was orange and a little bit of green appeared . For lab 2, aluminum foil and copper
chloride were obtained. The aluminum foil was placed in 5 drops of copper chloride. As
the aluminum foil sat in the copper chloride it began rusting. All the pieces of the
aluminum foil touching the copper chloride rusted. In lab 3, nickel (II) chloride and
sodium phosphate were obtained. Five drops of the nickel (II) chloride were placed into a
clean cell well. Then five drops of sodium chloride were added to that and a white
precipitate was produced quickly. In lab 4, manganese (IV) and hydrogen peroxide were
collected. Five drops of hydrogen peroxide were added to a clean cell well and a very
small amount of manganese (IV) was added to that. The reaction observed was that the
hydrogen peroxide was tinted grey. Lab 6 was done next, copper (II) nitrate and sodium
hydroxide were obtained. Five drops of copper (II) nitrate were added to a clean cell well
and then five drops of sodium hydroxide were added to that. First, the Copper (II) nitrate
got clearer and then cloudy grains of white precipitate appeared. In lab 5, a candle, zinc,
and hydrochloric acid were obtained. First the zinc was placed on a watch glass and 10
drops of hydrochloric acid were added to it, and it began fizzing and sizzling. Then the
candle was lit and a wooden splint was held over the candle until it was lit. The lit
wooden splint was then held over the zinc and hydrochloric acid mixture and it caused a
popping noise.
Results
Exp #
Reactants
Pre-observations
Post-Observations
Rxn Type
1 Methane gas + Oxygen
Bunsen burner was
just sitting there
with no flame
There was two cones of flame one a lighter
blue than the other.
B: 1.1.1
2 Magnesium
Magnesium was
flat and silver
Burned ashes and (fine powdery) dust.
Grayish in color
C:1.1.1
Copper (II) Chloride +
4 Aluminum
Copper was curly
and goldish in color
Copper chloride
was in a dish and
was blue, the
aluminum stayed
silver.
Nickel (II) Chloride +
5 Sodium Phosphate
Cloudy mixture
starting to combine.
Turned white and became a PPT.
DR: 3.2.1.6
hydrogen peroxide +
6 manganese (IV) oxide
The magnesium
oxide increases the
rate.
Tinted the water grey, no visible reaction.
D: 2.2.1
zinc + hydrochloric
7 acid
Was just sitting
there color?
Texture?
Fizzes and bubbles. Made a popping noise.
SR: 2.4.2.2
copper (II) nitrate +
8 sodium hydroxide
Was clear with a
hint of blue coloring
and separate.
Started to mix together and formed whit PPT
but stayed blue.
DR: 1.2.1.2
3 Copper (II) + Oxygen
Copper just turned orangeish and turned to
ashes.
C: 1.2.2
C: 1.1.1
The copper chloride turned the aluminum to a
rusty orange color and bubbled a little bit.
SR: 3.2.2.3
Conclusion
In lab one magnesium and oxygen were reacted and based on the observations
that magnesium turned to ash. It’s predicted that the product will be magnesium oxide.
Also copper and oxygen reacted and based on the fact that the copper wire burned away,
it's predicted to produce copper oxide. The conclusion for burning the magnesium was
Mg + O2  MgO which is a combination (why?) reaction of 1.1.1. The reaction for
burning the copper was 2Cu + O2  2CuO which was combination (say why for each
type in each experiment) also, and it was 1.1.1. Also,
Cu + O2  CuO2 with 2.1.2.
The reason copper has two equations is because the lab doesn't specify what type of
copper it is and so two equations need to be done to figure out both possibilities.
In lab two copper chloride and aluminum foil were the reactants, and the
conclusions were that rust occurred on the aluminum. That leads to the prediction
that aluminum chloride and copper will be the product. Lab two's equation and reaction
was 3CuCl2 + 2Al  AlCl3 + 3Cu and it's a single replacement reaction, 3.2.2.3.
Lab three's reactants were nickel chloride and sodium phosphate and the
observations were that a white precipitate formed. That predicts that Ni3(PO4)2 + 6NaCl
will be formed. Lab three's reaction was3NiCl2 + 2Na3Po4  Ni3(PO4)2 + 6NaCl.
In lab four, hydrogen peroxide was the reactant, and the observations show that the
hydrogen peroxide just was tinted grey, with no sign of a visible reaction. The prediction
would end up being that water and oxygen were produced. Lab four's reaction was
2H2O2  2H2O + O2 and it was decomposition, 2.2.1.
In lab five, zinc was mixed with hydrochloric acid which caused a fizzing and
bubbling sound, the prediction of this reaction would be zinc hydride and chlorine. Lab
five's reaction was 2Zn + 4HCl  2ZnH2 + 2Cl2 and it was also single replacement with
2.4.2.2.
In lab six, copper nitrate was broken down. Observations show that was white
precipitate appeared and it was predicted the products would be copper hydroxide and
sodium nitrate. Lastly, lab six had the equation of Cu(NO3)2 + 2NaOH  CuOH2 +
2NaNO3 and it was double replacement 1.2.1.2.
In these labs you need to predict the outcome of reactions like a sports analyst
predicts the winning team. The products can be proven by figuring out the chemical
equation just like sports analysts can figure out the final outcome by watching the game.