word image
Lab Report

Chemistr­y Lab Report: Detailed Analysis of Chemical Reaction­s

1.991 Words / ~10 pages sternsternsternsternstern_0.2 Author Roland F. in Aug. 2012
<
>
Upload File
Genre/category

Lab Report
Chemistry

University, School

UCLA/ Los Angeles

Grade, Teacher, Year

1999, James

Author / Copyright
Roland F. ©
Metadata
Format: pdf
Size: 0.30 Mb
Without copy protection
Rating
sternsternsternsternstern_0.2
ID# 22225







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


  1. Burning methane: CH4 (g) + O2 (g) → 2H2O (g) + CO2 (g) Combustion


  1. Oxidation of Iron: 2Fe (III) (s) + 3O2 (g) → Fe2(O2)3 (s) Synthesis


  1. Thermal decomposition of Copper (II) Carbonate: CuCO3(S) → CuO(s) + CO2(g) Decomposition


  1. Lead (II) Nitrate and Potassium Iodide: Pb(NO3)2 (l) + 2KI(l) → PbI2 (l) + 2KNO3 (l) Double Displacement


  1. Copper Sulfate and Iron: Cu2SO4 (l) + Fe(II) → FeSO4(l) + 2Cu(s) Single Displacement


  1. Vinegar and baking soda: CH3COOH(l) + NaHCO3(s) → C2H3O3(l) + H2CO3 (l) Double Displacement


  1. Barium Chloride and Potassium Chromate: BaCl2(l) + K2CrO4(l) → BaCrO4(l) + 2KCl(s) Double Displacement


  1. Potassium Chromate and Silver Nitrate: K2CrO4(l) + 2AgNO3(l) → 2KNO3(s) + Ag2CrO4(l) Double Displacement


  1. Barium Chloride and Silver Nitrate: BaCl2 (l) + 2AgNO3 (l) → Ba(NO3)2 (l) + 2AgCl (l) Double Displacement


  1. 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. <


13



References & Links

Swap your papers