20 Feb i need pre lab and post lab from document 5, now send me pre lab, when i get the data you do post lab.Lab5-IdentificationofanUnkn
i need pre lab and post lab from document 5, now send me pre lab, when i get the data you do post lab.
Identification of an Unknown Salt by Determination of the Percentage Copper
Introduction to Percent Composition:
1) Percent composition is defined as the mass percentages of each element in a compound.
2) The mass percentage of element A in a compound is equal to the parts of A per hundred parts of the total, by mass.
a. The equation is as follows: Mass % A = (Mass of A in the compound / Mass of the entire compound) X 100%.
3) An example calculation for nitrobenzene, C6H5NO2
a. Step 1: Determine the molar mass of nitrobenzene.
i. Molar mass = (6 x 12.011 g/mol) + (5 x 1.0079 g/mol) + (1 x 14.0067 g/mol) + (2 x 15.9994 g/mol) = 123.11 g/mol
b. Step 2: Calculate the percent composition for each element.
i. C: (72.066 g/mol / 123.11 g/mol) x 100% = 58.54%
ii. H: (5.0395 g/mol / 123.11 g/mol) x 100% = 4.09%
iii. N: (14.0067 g/mol / 123.11 g/mol) x 100% = 11.38%
iv. O: (31.9988 g/mol / 123.11 g/mol) x 100% = 25.99%
Introduction to the Reactivity Series:
1) A single displacement (single replacement) reaction occurs when an element reacts with a compound to displace an element from that compound.
a. Example #1: Zn(s) + 2AgNO3(aq) ( Zn(NO3)2(aq) + 2Ag(s)
b. Example #2: 2Al(s) + 6HCl(aq) ( 2AlCl3(aq) + 3H2(g)
2) Whether a reaction takes place depends on the relative reactivity of the elemental metal to the displaced element.
a. If the elemental metal is more reactive than the displaced element, then a reaction will take place.
b. If the elemental metal is less reactive than the displaced element, then a reaction will NOT take place.
3) The reactivity series provides a list of the common metals in order of decreasing reactivity (from the most reactive to the least.)
a. The reactivity series is as follows: Li, K, Ba, Ca, Na, Mg, Al, Zn, Cr, Fe, Cd, Co, Ni, Sn, Pb, H2, Cu, Hg, Ag, Au
4) The reactivity series also reveals which elements react with water and/or acids to produce hydrogen gas.
a. Metals lithium to sodium (Li–Na) react violently with liquid water (and acid) to produce hydrogen gas.
b. Metals magnesium to cadmium (Mg–Cd) react slowly with liquid water but considerably with acids to produce hydrogen gas.
c. Metals cobalt to lead (Co–Pb) do NOT react with liquid water but considerably with acids to produce hydrogen gas.
d. Metals copper to gold (Cu–Au) react neither with liquid water nor acids.
The Copper Salts*:
1) Cu3(PO4)2 • 3H2O
2) CuCl2 • 2H2O
3) CuSO4 • 5H2O
4) Cu(ClO4)2 • 6H2O
5) CuSeO4 • 5H2O
6) Cu(CH3CO2)2 • H2O
Substances to include in the Table of Chemical and Physical Properties:
Prepare this table and all the compounds used in the experiment and complete the data table “Percent Copper in the Reactants”.
Procedure:
1) On an analytical balance, weigh out 1.0 grams of the unknown copper salt in a weigh boat or on a piece of weigh paper.
a. Record the unknown number/letter and the color of the salt in your lab notebook.
b. Record the mass in your lab notebook.
2) Transfer the unknown copper salt into a 100 mL beaker.
a. Ensure all powder is in the beaker; avoid spilling.
b. If material clings to weigh boat, transfer into the beaker using the deionized water in the next step.
3) Using a 100 mL graduated cylinder, obtain 30.0 mL of deionized water and add to the beaker containing the unknown copper salt.
4) Place beaker onto a hot plate.
5) Gently heat the solution to dissolve salt.
a. Stir with a glass stir rod until dissolved.
b. Do NOT allow for a significant boil.
6) Weigh out 1.0 grams of mossy zinc and cautiously add to the solution.
a. Do NOT allow any of the liquid material to splash out.
7) Continue heating the solution using a stirring rod to mix thoroughly.
a. Do NOT allow for a significant boil.
b. Do NOT remove the stirring rod from the beaker; some of the copper solution will cling to the glass.
8) Continue stirring the heated solution until the solution color completely fades.
a. Add an additional 0.3 g of mossy zinc if all zinc reacts and the color remains.
9) Once the solution is completely colorless, discontinue heating and allow to cool for a few minutes.
10) Obtain 5.0 mL of 6.0 M sulfuric acid.
11) After cooling for a few minutes, slowly add the sulfuric acid to the solution 0.5 mL at a time.
a. This addition step should take at least 5 minutes.
b. This step is to remove unreacted zinc.
12) A few minutes after this addition, remove all chunks of unreacted zinc with forceps.
a. Be careful to rinse off all bits of zinc with deionized water before removing from the solution.
13) Obtain a piece of filter paper and a watch glass and record the mass on an analytical balance.
14) Create a cone with the filter paper by folding it in half twice to form a quarter of a circle and then separating one side from the other three.
15) Place filter paper into a glass filter and then place filter onto a 500 mL or smaller Erlenmeyer flask.
16) Wet the filter with a small amount of deionized water.
a. Ensure that you remove the bubbles between the filter paper and funnel.
17) Once the filter paper is secure, transfer the contents of the beaker into the filter paper.
a. The water should pass through the filter leaving behind the copper.
b. Do not allow the liquid volume to exceed the height of the filter paper.
c. Ensure all copper is collected in the filter.
18) Use the glass rod to assist the transfer into the filter paper.
19) Add 1.5 mL of 6M sulfuric acid to approximately 15.0 mL of deionized water and rinse collected copper.
a. This step is necessary to ensure zinc has been eliminated.
20) Following the addition of the acid rinse, wash thoroughly with copious amounts of deionized water.
a. If some acid remains, the filter paper will burn in the oven.
b. Ensure the filter paper is free from acid.
21) After the filter paper has drained from the last rinse, transfer filter paper with contents onto the pre–weighed watch glass.
22) Place sample into a steam bath (boil 30 mL of water in a 100 mL beaker using hot plate).
a. Allow at least 20 minutes to ensure dryness.
23) Once dry, carefully remove from the oven and allow to cool to room temperature.
24) Once cool, obtain the mass of the sample.
Clean – Up:
25) Rinse all filtrates down the sink with plenty of water.
26) All copper and unreacted zinc should be placed in the appropriate waste containers.
Sample Data Table for Percent Copper in Reactants:
|
No. |
Formula of Copper Salt |
IUPAC Name |
Molar Mass (g/mol) |
Percent Copper |
|
1 |
Cu3(PO4)2 • 3H2O |
|||
|
2 |
CuCl2 • 2H2O |
|||
|
3 |
CuSO4 • 5H2O |
|||
|
4 |
Cu(ClO4)2 • 6H2O |
|||
|
5 |
CuSeO4 • 5H2O |
|||
|
6 |
Cu(CH3CO2)2 • H2O |
Sample Data Table:
a) Unknown number/letter of copper salt: ________
b) Mass of unknown copper salt in grams: ________
c) Mass of mossy zinc in grams: ________
d) Mass of watch glass + filter paper in grams: ________
e) Mass of watch glass + filter paper + copper in grams: ________
f) Mass of copper in grams (e – d): ________
g) Experimental percent copper in salt (f/b X 100%): __________
h) Identity of copper salt based on percent copper: ________
i) Balanced equation for the reaction: _____________________________
j) Balanced equation for zinc elimination: __________________________
Banerjee
General Chemistry-I Lab
*Notice all solid copper salts are available as hydrates. When dissolved in water, they are no longer hydrates.
PAGE
5
,
Pre-lab 4
Title: Periodic Trends
Date: 9/12/18
Unknown: N/A
Purpose: The purpose is to observe chemical properties of elements in periods (rows) and in
groups/families (columns).
Balanced Equations:
Part 1: Chemical Properties of the Alkaline Earth Metal Nitrates
Mg(NO3)2(aq) + Na2CO3(aq) MgCO3(s) + 2NaNO3(aq)
Ca(NO3)2(aq) + Na2CO3(aq) CaCO3(s) + 2NaNO3(aq)
Ba(NO3)2(aq) + Na2CO3(aq) BaCO3(s) + 2NaNO3(aq)
Part 2: Chemical Properties of the Halides
NaCl(aq) + AgNO3(aq) AgCl(s) + NaNO3(aq)
NaBr(aq) + AgNO3(aq) AgBr(s) + NaNO3(aq)
NaI(aq) + AgNO3(aq) AgI(s) + NaNO3(aq)
Part 3: Reactivity of Third Period Elements with Oxygen
2 Mg(s) + O2(g) 2 MgO(s)
4 Al(s) + 3 O2(g) 2 Al2O3(s)
Si(s) + O2(g) SiO2(s)
Part 4: Reactivity of Third Period Elements with Hydrochloric Acid
Mg(s) + 2 HCl(aq) MgCl2(aq) + H2(g)
2 Al(s) + 6 HCl(aq) 2 AlCl3(aq) + 3 H2(g)
Si(s) + 4 HCl(aq) SiCl4(aq) + 2 H2(g)
Table of Chemical and Physical Properties:
Chemical Name Molecular
Weight
Boiling Point Density Safety
Barium nitrate
Ba(NO3)2
261.34
529 C 3.24 g/cm
3 Poisonous. Do
not mix with
flammable
materials.
Silver nitrate
AgNO3
169.87 440 C 4.35 g/cm 3 Corrosive and
toxic. Avoid
skin contact.
Sodium Chloride
NaCl
58.44 801 C (melting
point)
2.16 g/cm3 Nonhazardous
Magnesium
Mg
24.31 650 C (melting
point)
1.738 g/cm3 Flammable. Do
not stare are
flame during
reaction with
magnesium and
oxygen
Calcium
Ca
40.08 842 C (melting
point)
1.54 g/cm3 Flammable
gases produced
with in contact
with water
Aluminum
Al
26.98 2460 C 2.7 g/cm 3 Flammable
Silicon
Si
28.09 2355 C 2.33 g/ml Nonhazardous
Oxygen
O
15.999 u 90.188 K 1.429 g/L Flammable gas
Hydrochloric
acid
HCl
36.46 110 C 1.18 g/cm 3 Toxic and
corrosive. Can
cause irritation
or burns to skin.
Procedure Observation
Part 1
1. Add 1ml of each solution to each labeled test tubes
2. Add about three drops of solution from tube 4 into tubes 1-3 and record
observations.
Part 2
3. Repeat steps 1&2 for part 2 with different solutions
Part 3
4. On a watch glass, add small pieces of magnesium, aluminum and silicon and
observe physical appearances.
5. Take turns placing each substance over an open flame and record
observations.
Part 4
6. Place a small piece of magnesium, aluminum, and silicon in separate test
tubes and label appropriately.
7. Place 1ml of HCl into each test tube and record observations.
Data Collected:
Part 1
Aqueous
substances
Observations after reacting with 0.02 M Na2CO3
Mg(NO3)2
Ca(NO3)2
Ba(NO3)2
Part 2
Aqueous
substances
Observations after reacting with 0.10 M AgNO3
NaCl
NaBr
NaI
Part 3
Metallic
substances
Observations during and after reaction with atmospheric O2
Mg
Al
Si
Part 4
Metallic
substances
Observations during and after reaction with aqueous HCl
Mg
Al
Si
Discussion:
Conclusion:
Date Completed & Signature:
,
Pre-lab 4
Title: Periodic Trends
Date: 9/12/18
Unknown: N/A
Purpose: The purpose is to observe chemical properties of elements in periods (rows) and in
groups/families (columns).
Balanced Equations:
Part 1: Chemical Properties of the Alkaline Earth Metal Nitrates
Mg(NO3)2(aq) + Na2CO3(aq) MgCO3(s) + 2NaNO3(aq)
Ca(NO3)2(aq) + Na2CO3(aq) CaCO3(s) + 2NaNO3(aq)
Ba(NO3)2(aq) + Na2CO3(aq) BaCO3(s) + 2NaNO3(aq)
Part 2: Chemical Properties of the Halides
NaCl(aq) + AgNO3(aq) AgCl(s) + NaNO3(aq)
NaBr(aq) + AgNO3(aq) AgBr(s) + NaNO3(aq)
NaI(aq) + AgNO3(aq) AgI(s) + NaNO3(aq)
Part 3: Reactivity of Third Period Elements with Oxygen
2 Mg(s) + O2(g) 2 MgO(s)
4 Al(s) + 3 O2(g) 2 Al2O3(s)
Si(s) + O2(g) SiO2(s)
Part 4: Reactivity of Third Period Elements with Hydrochloric Acid
Mg(s) + 2 HCl(aq) MgCl2(aq) + H2(g)
2 Al(s) + 6 HCl(aq) 2 AlCl3(aq) + 3 H2(g)
Si(s) + 4 HCl(aq) SiCl4(aq) + 2 H2(g)
Table of Chemical and Physical Properties:
Chemical Name Molecular
Weight
Boiling Point Density Safety
Barium nitrate
Ba(NO3)2
261.34
529 C 3.24 g/cm
3 Poisonous. Do
not mix with
flammable
materials.
Silver nitrate
AgNO3
169.87 440 C 4.35 g/cm 3 Corrosive and
toxic. Avoid
skin contact.
Sodium Chloride
NaCl
58.44 801 C (melting
point)
2.16 g/cm3 Nonhazardous
Magnesium
Mg
24.31 650 C (melting
point)
1.738 g/cm3 Flammable. Do
not stare are
flame during
reaction with
magnesium and
oxygen
Calcium
Ca
40.08 842 C (melting
point)
1.54 g/cm3 Flammable
gases produced
with in contact
with water
Aluminum
Al
26.98 2460 C 2.7 g/cm 3 Flammable
Silicon
Si
28.09 2355 C 2.33 g/ml Nonhazardous
Oxygen
O
15.999 u 90.188 K 1.429 g/L Flammable gas
Hydrochloric
acid
HCl
36.46 110 C 1.18 g/cm 3 Toxic and
corrosive. Can
cause irritation
or burns to skin.
Procedure Observation
Part 1
1. Add 1ml of each solution to each labeled test tubes
2. Add about three drops of solution from tube 4 into tubes 1-3 and record
observations.
Part 2
3. Repeat steps 1&2 for part 2 with different solutions
Part 3
4. On a watch glass, add small pieces of magnesium, aluminum and silicon and
observe physical appearances.
5. Take turns placing each substance over an open flame and record
observations.
Part 4
6. Place a small piece of magnesium, aluminum, and silicon in separate test
tubes and label appropriately.
7. Place 1ml of HCl into each test tube and record observations.
All observations are documented in the data
tables below
Data Collected:
Part 1
Aqueous
substances
Observations after reacting with 0.02 M Na2CO3
Mg(NO3)2 No physical change observed
Ca(NO3)2 Semi-solid, cloudy substance formed and sunk to the bottom of the test tube
Ba(NO3)2 Solution became milky and slowly sunk to the bottom
Part 2
Aqueous
substances
Observations after reacting with 0.10 M AgNO3
NaCl Slow reaction. Started a bluish color and became milkier
NaBr Top layer of solution turned a milky color and slowly spread throughout
NaI Slow reaction. Went from a translucent yellow to a bluish color
Part 3
Metallic
substances
Observations during and after reaction with atmospheric O2
Mg Produced a bright white flame and sparks
Al The aluminum turned bight orange and produced an orange flame
Si No reaction observed
Part 4
Metallic
substances
Observations during and after reaction with aqueous HCl
Mg Immediately bubbled. Condensation and steam produced. Test tube was warm
Al Slow reaction. Solution bubbled and aluminum piece dissolved in solution
Si No reaction observed
Discussion:
In this lab we observed physical and chemical properties. For example, we observed a
chemical reaction when magnesium was introduced to oxygen. It produced a bright white flame.
Changes in color are physical changes like when AgNO3 was introduced to NaI.
Conclusion:
Some chemicals are more reactive than other. We can observe physical and some
chemical changes when we mixing chemicals together.
Date Completed & Signature:
,
Banerjee
The lab notebook guidelines are included in this document.
1. Each lab period, in addition to coming to lab properly dressed, a pre-lab must be
prepared for the lab you are scheduled to perform that day. Failure to come to lab
without a complete pre-lab and improper dress will result in dismissal from the week’s
lab with a zero point allocation.
a. Each pre-lab should include the following sections: Name, Title, Date, Unknown,
Purpose, Balanced Equations, Table of Chemical and Physical Properties,
Procedure and an incomplete data table under Data Collected. This should be
uploaded on CANVAS before the start of lab and will be scanned for plagiarism.
This is due at the beginning of the lab period (mandatory).
2. Do not leave without checking out with your professor. You are allowed to use any
notebook or electronic notebook for this lab. Binded lab notebook is not needed for this
lab.
3. Lab reports (post-lab) are due 1 week following the completion of a lab. Each lab is
worth 100 points, comprising of pre and post lab. Your professor will provide further
instructions for completing your lab report.
a. Reports that are suspected to be plagiarized will be reported to the Dean, as
potential violators of the Academic Dishonesty guidelines (procedure 5026). This
will result in an F in the class. Self-plagiarism is also considered plagiarism.
4. The final lab report (post-lab) should comprise of 1) pre-lab sections, 2) Data collected,
3) Observations, 4) Discussion and 5) Conclusion and should be uploaded to CANVAS
placeholder.
Please upload at correct placeholder for each lab. Resubmissions are not allowed.
Please keep an eye on similarity score after submission.
Banerjee
Laboratory Notebook Guidelines
A proper laboratory notebook is one from which a given laboratory experiment can be repeated
by another chemist. Another chemist, chemical engineer or chemical patent lawyer should be
able to read your notebook and understand what you did and the results you obtained.
1. Every experiment should include the following sections listed below.
Title
Name
Date
Unknown (if any)
Purpose Describe the goal of the experiment.
Balanced Equation(s) (if any)
Table of Chemical and Physical Properties (including reference information, if
necessary)
Procedure & Do not provide a detailed, step-by-step procedure. The procedure is in
numerical form and should give the reader a general description of the procedure and any
special experimental details.
Observations . Throughout the lab, be sure to include any relevant observations: What
mass or volume did YOU use? Was the product a solid, liquid, gel, red precipitate, green
solution, etc?
Data Collected A sample data table is provided in each lab write-up. Record the
quantities of materials you used in the experiment. This includes calculations using
formulas, percent yield, percent error, etc.
Discussion Discussion should correlate expected data with obtained data in scientific
terms, without personal opinion.
Conclusion Conclusion should scientifically critic the success of the experiment, without
personal opinion and without over emphasis on errors.
The following sections must be completed prior to lab in the form of PRE-lab and uploaded to
CANVAS in correct placeholder: Name, Title, Date, Unknown, Purpose, Balanced Equations,
Table of Chemical and Physical Properties, Procedure and an incomplete data table under Data
Collected.
** All post-labs are due at the beginning of the next lab period on CANVAS, unless otherwise
specified. Each lab write-up is worth 100 points, including pre and post lab.
Banerjee
Lab reports must be written independently of lab partners,
students in other lab sections, and previous semesters’
students. Reports that are suspected to be plagiarized from any
of the previous sources will be submitted to the Dean, as
potential violators of the Academic Dishonesty guidelines
(procedure 5026). This will result in an F in the class.
THE FOLLOWING PAGE HAS A TEMPLATE ATTACHED FOR YOUR
CONVENIENCE:
Banerjee
Pre-lab
Your Name:
Title:
Date:
Unknown: (if none, write N/A)
(skip one line)
Purpose: Describe the goal of the experiment. Your purpose should answer the following: What are you doing? Why are you doing it? How are you going do it?
This should be in your own words. (skip one line)
Balanced Equations: (if none, write N/A)
(skip one line)
Table of Chemical and Physical Properties: The chemicals and physical/chemical properties listed in the lab should be included in the table.
All the information can obtained from sigmaaldrich dot com.
Example:
Chemical
Name
Molecular
Weight
(g/mol)
Boiling
Point
(°C)
Density Safety
zinc 65.35 907 7.14
g/cm3
irritant,
combustible
copper
nickel
lead
polypropylene
water
Information obtained from:
http://www.sciencelab.com/msds.php?msdsId=9925476
http://pslc.ws/macrog/pp.htm
Banerjee
Procedure 1. Obtain 50 mL H2O. 2. Tare graduated cylinder
on a balance.
3. Add a rubber stopper, after recording size.
Observations: Actual volume: xx mL
Color change:
Gas evolution:
Temperature change:
Data Collected: The provided data table can be pasted into this section or rewritten for each lab. Include calculations for theoretical yield, actual yield,
percent yield, percent error, and any other calculations that were performed in the
completion of the data table.
(skip one line)
Discussion: Discussion should correlate expected data with obtained data in scientific terms, without personal opinion.
Conclusion: Conclusion should scientifically critic the success of the experiment, without personal opinion and without over emphasis on errors.
Contents of discussion and conclusion together should not exceed five scientifically written
sentences.
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