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Project 1: Identification of Inorganic Salts
Antonio Morales
CHS-2440L
I.
Introduction
1 page:
- where you describe why you did the experiment
- describe the theory about the different test
- describe what you did to prove the theory
The ability to determine an unknown sample of a compound is incredible because it opens a
world of possibilities. Whether if it is identifying something form other space or an athlete
doping himself, these abilities allows us to find the unknown. In order to find the solutions, one
has to do several tests both qualitative and quantitative.
This project is based on determining the identity of a compound based on unique properties that
define that compound. By performing quantitative and qualitative analysis, like a gravimetric
analysis for the former and flame test for the later. Also, we observed how this known salt
reacted with different compounds. With the result obtained and some calculations made we can
assume the compound because we are measuring it properties both physical and chemical.
II.
Procedures and methods
A. Preparation of a 1wt% solution for Unknown and “salt used”
B. pH Testing
C. Solubility test
D. Conductivity Testing
E. Flame Test
F. Precipitation test with Silver Nitrate and Barium Chloride
G. Preparation of solutions for gravimetric analysis
H. Gravimetric analysis
Table 1: Safety information
Chemical
Potential Danger
Precautions
Barium Nitrate
Potential Acute Health Effects:
Extremely hazardous in case of
ingestion. Very hazardous in
case of skin contact (irritant), of
eye contact (irritant), of
inhalation. Prolonged exposure
may result in skin burns and
ulcerations. Over-exposure by
inhalation may cause respiratory
irritation. Inflammation of the eye
is characterized by redness,
watering, and itching. Skin
inflammation is characterized by
itching, scaling, reddening, or,
occasionally, blistering.
Eye Contact: Check for and
remove any contact lenses. In
case of contact, immediately
flush eyes with plenty of water for
at least 15 minutes. Cold water
may be used. Get medical
attention immediately.
Potential Chronic Health
Effects: Extremely hazardous in
case of ingestion. Very
hazardous in case of skin contact
(irritant), of eye contact (irritant),
Skin Contact: In case of contact,
immediately flush skin with plenty
of water for at least 15 minutes
while removing contaminated
clothing and shoes. Cover the
irritated skin with an emollient.
Cold water may be used. Wash
clothing before reuse. Thoroughly
clean shoes before reuse. Get
medical attention immediately.
Serious Skin Contact: Wash
with a disinfectant soap and
of inhalation. CARCINOGENIC
EFFECTS: Not available.
MUTAGENIC EFFECTS: Not
available. TERATOGENIC
EFFECTS: Not available.
DEVELOPMENTAL TOXICITY:
Not available. The substance is
toxic to kidneys, lungs, the
nervous system. Repeated or
prolonged exposure to the
substance can produce target
organs damage. Repeated or
prolonged inhalation of dust may
lead to chronic respiratory
irritation.
Calcium Nitrate
Potential Acute Health Effects:
Hazardous in case of skin contact
(irritant), of eye contact (irritant),
of ingestion, of inhalation. Slightly
hazardous in case of skin contact
(permeator). Prolonged exposure
may result in skin burns and
ulcerations. Over-exposure by
inhalation may cause respiratory
irritation.
Potential Chronic Health
Effects: CARCINOGENIC
EFFECTS: Not available.
MUTAGENIC EFFECTS: Not
available. TERATOGENIC
EFFECTS: Not available.
DEVELOPMENTAL TOXICITY:
Not available. The substance is
toxic to lungs, mucous
membranes. Repeated or
prolonged exposure to the
substance can produce target
organs damage.
cover the contaminated skin with
an anti-bacterial cream. Seek
immediate medical attention.
Inhalation: If inhaled, remove to
fresh air. If not breathing, give
artificial respiration. If breathing is
difficult, give oxygen. Get medical
attention.
Serious Inhalation: Evacuate
the victim to a safe area as soon
as possible. Loosen tight clothing
such as a collar, tie, belt or
waistband. If breathing is difficult,
administer oxygen. If the victim is
not breathing, perform mouth-tomouth resuscitation. Seek
medical attention.
Ingestion: Do NOT induce
vomiting unless directed to do so
by medical personnel. Never give
anything by mouth to an
unconscious person. If large
quantities of this material are
swallowed, call a physician
immediately. Loosen tight
clothing such as a collar, tie, belt
or waistband.
Eye Contact: Check for and
remove any contact lenses.
Immediately flush eyes with
running water for at least 15
minutes, keeping eyelids open.
Cold water may be used. Do not
use an eye ointment. Seek
medical attention.
Skin Contact: After contact with
skin, wash immediately with
plenty of water. Gently and
thoroughly wash the
contaminated skin with running
water and non-abrasive soap. Be
particularly careful to clean folds,
crevices, creases and groin. Cold
water may be used. Cover the
irritated skin with an emollient. If
irritation persists, seek medical
attention.
Serious Skin Contact: Wash
with a disinfectant soap and
cover the contaminated skin with
an anti-bacterial cream. Seek
medical attention. Inhalation:
Allow the victim to rest in a well
ventilated area. Seek immediate
medical attention.
Serious Inhalation: Evacuate
the victim to a safe area as soon
as possible. Loosen tight clothing
such as a collar, tie, belt or
waistband. If breathing is difficult,
administer oxygen. If the victim is
not breathing, perform mouth-tomouth resuscitation. Seek
medical attention.
Hydrochloric Acid
Potential Acute Health Effects:
Very hazardous in case of skin
contact (corrosive, irritant,
permeator), of eye contact
(irritant, corrosive), of ingestion, .
Slightly hazardous in case of
inhalation (lung sensitizer). Noncorrosive for lungs. Liquid or
spray mist may produce tissue
damage particularly on mucous
membranes of eyes, mouth and
respiratory tract. Skin contact
may produce burns. Inhalation of
the spray mist may produce
severe irritation of respiratory
tract, characterized by coughing,
choking, or shortness of breath.
Severe over-exposure can result
in death. Inflammation of the eye
is characterized by redness,
watering, and itching. Skin
inflammation is characterized by
itching, scaling, reddening, or,
occasionally, blistering.
Potential Chronic Health
Effects: Slightly hazardous in
case of skin contact (sensitizer).
CARCINOGENIC EFFECTS:
Classified 3 (Not classifiable for
human.) by IARC [Hydrochloric
acid]. MUTAGENIC EFFECTS:
Ingestion: Do not induce
vomiting. Loosen tight clothing
such as a collar, tie, belt or
waistband. If the victim is not
breathing, perform mouth-tomouth resuscitation. Seek
immediate medical attention.
Eye Contact: Check for and
remove any contact lenses. In
case of contact, immediately
flush eyes with plenty of water for
at least 15 minutes. Cold water
may be used. Get medical
attention immediately.
Skin Contact: In case of contact,
immediately flush skin with plenty
of water for at least 15 minutes
while removing contaminated
clothing and shoes. Cover the
irritated skin with an emollient.
Cold water may be used.Wash
clothing before reuse. Thoroughly
clean shoes before reuse. Get
medical attention immediately.
Serious Skin Contact: Wash
with a disinfectant soap and
cover the contaminated skin with
an anti-bacterial cream. Seek
immediate medical attention.
Inhalation: If inhaled, remove to
fresh air. If not breathing, give
artificial respiration. If breathing is
difficult, give oxygen. Get medical
attention immediately.
Not available. TERATOGENIC
EFFECTS: Not available.
DEVELOPMENTAL TOXICITY:
Not available. The substance
may be toxic to kidneys, liver,
mucous membranes, upper
respiratory tract, skin, eyes,
Circulatory System, teeth.
Repeated or prolonged exposure
to the substance can produce
target organs damage. Repeated
or prolonged contact with spray
mist may produce chronic eye
irritation and severe skin irritation.
Repeated or prolonged exposure
to spray mist may produce
respiratory tract irritation leading
to frequent attacks of bronchial
infection. Repeated exposure to a
highly toxic material may produce
general deterioration of health by
an accumulation in one or many
human organs.
Acetone
Potential Acute Health Effects:
Hazardous in case of skin contact
(irritant), of eye contact (irritant),
of ingestion, of inhalation. Slightly
hazardous in case of skin contact
(permeator).
Potential Chronic Health
Effects: CARCINOGENIC
EFFECTS: A4 (Not classifiable
for human or animal.) by ACGIH.
MUTAGENIC EFFECTS: Not
available. TERATOGENIC
EFFECTS: Not available.
DEVELOPMENTAL TOXICITY:
Classified Reproductive
system/toxin/female,
Reproductive system/toxin/male
[SUSPECTED]. The substance is
toxic to central nervous system
(CNS). The substance may be
toxic to kidneys, the reproductive
system, liver, skin. Repeated or
prolonged exposure to the
substance can produce target
organs damage.
Serious Inhalation: Evacuate
the victim to a safe area as soon
as possible. Loosen tight clothing
such as a collar, tie, belt or
waistband. If breathing is difficult,
administer oxygen. If the victim is
not breathing, perform mouth-tomouth resuscitation. WARNING:
It may be hazardous to the
person providing aid to give
mouth-to-mouth resuscitation
when the inhaled material is
toxic, infectious or corrosive.
Seek immediate medical
attention.
Ingestion: If swallowed, do not
induce vomiting unless directed
to do so by medical personnel.
Never give anything by mouth to
an unconscious person. Loosen
tight clothing such as a collar, tie,
belt or waistband. Get medical
attention immediately.
Eye Contact: Check for and
remove any contact lenses.
Immediately flush eyes with
running water for at least 15
minutes, keeping eyelids open.
Cold water may be used. Get
medical attention.
Skin Contact: In case of contact,
immediately flush skin with plenty
of water. Cover the irritated skin
with an emollient. Remove
contaminated clothing and shoes.
Cold water may be used.Wash
clothing before reuse. Thoroughly
clean shoes before reuse. Get
medical attention.
Serious Skin Contact: Wash
with a disinfectant soap and
cover the contaminated skin with
an anti-bacterial cream. Seek
medical attention.
Inhalation: If inhaled, remove to
fresh air. If not breathing, give
artificial respiration. If breathing is
difficult, give oxygen. Get medical
attention if symptoms appear.
Serious Inhalation: Evacuate
the victim to a safe area as soon
as possible. Loosen tight clothing
such as a collar, tie, belt or
waistband. If breathing is difficult,
administer oxygen. If the victim is
not breathing, perform mouth-tomouth resuscitation. Seek
medical attention.
Ethanol
Potential Acute Health Effects:
Hazardous in case of skin contact
(irritant), of eye contact (irritant),
of inhalation. Slightly hazardous
in case of skin contact
(permeator), of ingestion.
Potential Chronic Health
Effects: Slightly hazardous in
case of skin contact (sensitizer).
CARCINOGENIC EFFECTS: A4
(Not classifiable for human or
animal.) by ACGIH. MUTAGENIC
EFFECTS: Mutagenic for
mammalian somatic cells.
Mutagenic for bacteria and/or
yeast. TERATOGENIC
EFFECTS: Classified PROVEN
for human. DEVELOPMENTAL
TOXICITY: Classified
Development toxin [PROVEN].
Classified Reproductive
system/toxin/female,
Reproductive system/toxin/male
[POSSIBLE]. The substance is
toxic to blood, the reproductive
system, liver, upper respiratory
tract, skin, central nervous
system (CNS). Repeated or
prolonged exposure to the
substance can produce target
organs damage.
Ingestion: Do NOT induce
vomiting unless directed to do so
by medical personnel. Never give
anything by mouth to an
unconscious person. Loosen tight
clothing such as a collar, tie, belt
or waistband. Get medical
attention if symptoms appear.
Eye Contact: Check for and
remove any contact lenses.
Immediately flush eyes with
running water for at least 15
minutes, keeping eyelids open.
Cold water may be used. Get
medical attention.
Skin Contact: In case of contact,
immediately flush skin with plenty
of water. Cover the irritated skin
with an emollient. Remove
contaminated clothing and shoes.
Cold water may be used.Wash
clothing before reuse. Thoroughly
clean shoes before reuse. Get
medical attention.
Serious Skin Contact: Wash
with a disinfectant soap and
cover the contaminated skin with
an anti-bacterial cream. Seek
medical attention.
Inhalation: If inhaled, remove to
fresh air. If not breathing, give
artificial respiration. If breathing is
difficult, give oxygen. Get medical
attention if symptoms appear.
Serious Inhalation: Evacuate
the victim to a safe area as soon
as possible. Loosen tight clothing
such as a collar, tie, belt or
waistband. If breathing is difficult,
administer oxygen. If the victim is
not breathing, perform mouth-to-
mouth resuscitation. Seek
medical attention.
Silver Nitrate
Potential Acute Health Effects:
Very hazardous in case of skin
contact (irritant), of ingestion.
Hazardous in case of skin contact
(permeator), of eye contact
(irritant), of inhalation. Slightly
hazardous in case of skin contact
(corrosive). The amount of tissue
damage depends on length of
contact. Eye contact can result in
corneal damage or blindness.
Skin contact can produce
inflammation and blistering.
Inhalation of dust will produce
irritation to gastro-intestinal or
respiratory tract, characterized by
burning, sneezing and coughing.
Severe over-exposure can
produce lung damage, choking,
unconsciousness or death.
Prolonged exposure may result in
skin burns and ulcerations. Overexposure by inhalation may
cause respiratory irritation.
Potential Chronic Health
Effects: CARCINOGENIC
EFFECTS: Not available.
MUTAGENIC EFFECTS: Not
available. TERATOGENIC
EFFECTS: Not available.
DEVELOPMENTAL TOXICITY:
Not available. The substance is
toxic to lungs. The substance
may be toxic to mucous
membranes, skin, eyes.
Repeated or prolonged exposure
to the substance can produce
target organs damage. Repeated
exposure of the eyes to a low
level of dust can produce eye
irritation. Repeated skin exposure
can produce local skin
destruction, or dermatitis.
Ingestion: Do NOT induce
vomiting unless directed to do so
by medical personnel. Never give
anything by mouth to an
unconscious person. Loosen tight
clothing such as a collar, tie, belt
or waistband. Get medical
attention if symptoms appear.
Eye Contact: Check for and
remove any contact lenses. In
case of contact, immediately
flush eyes with plenty of water for
at least 15 minutes. Cold water
may be used. Get medical
attention.
Skin Contact: In case of contact,
immediately flush skin with plenty
of water for at least 15 minutes
while removing contaminated
clothing and shoes. Cover the
irritated skin with an emollient.
Cold water may be used.Wash
clothing before reuse. Thoroughly
clean shoes before reuse. Get
medical attention immediately.
Serious Skin Contact: Wash
with a disinfectant soap and
cover the contaminated skin with
an anti-bacterial cream. Seek
immediate medical attention.
Inhalation: If inhaled, remove to
fresh air. If not breathing, give
artificial respiration. If breathing is
difficult, give oxygen. Get medical
attention.
Serious Inhalation: Evacuate
the victim to a safe area as soon
as possible. Loosen tight clothing
such as a collar, tie, belt or
waistband. If breathing is difficult,
administer oxygen. If the victim is
not breathing, perform mouth-tomouth resuscitation. WARNING:
It may be hazardous to the
person providing aid to give
mouth-to-mouth resuscitation
when the inhaled material is
Repeated inhalation of dust can
produce varying degree of
respiratory irritation or lung
damage.
Sodium Carbonate
Potential Acute Health Effects:
Hazardous in case of skin contact
(irritant), of eye contact (irritant),
of ingestion, of inhalation (lung
irritant).
Potential Chronic Health
Effects: Slightly hazardous in
case of skin contact (sensitizer).
CARCINOGENIC EFFECTS: Not
available. MUTAGENIC
EFFECTS: Not available.
TERATOGENIC EFFECTS: Not
available. DEVELOPMENTAL
TOXICITY: Not available. The
substance may be toxic to upper
respiratory tract, skin, eyes.
Repeated or prolonged exposure
to the substance can produce
target organs damage.
toxic, infectious or corrosive.
Seek immediate medical
attention.
Ingestion: Do NOT induce
vomiting unless directed to do so
by medical personnel. Never give
anything by mouth to an
unconscious person. If large
quantities of this material are
swallowed, call a physician
immediately. Loosen tight
clothing such as a collar, tie, belt
or waistband.
Eye Contact: Check for and
remove any contact lenses. In
case of contact, immediately
flush eyes with plenty of water for
at least 15 minutes. Cold water
may be used. Get medical
attention.
Skin Contact: In case of contact,
immediately flush skin with plenty
of water. Cover the irritated skin
with an emollient. Remove
contaminated clothing and shoes.
Cold water may be used.Wash
clothing before reuse. Thoroughly
clean shoes before reuse. Get
medical attention.
Serious Skin Contact: Wash
with a disinfectant soap and
cover the contaminated skin with
an anti-bacterial cream. Seek
immediate medical attention.
Inhalation: If inhaled, remove to
fresh air. If not breathing, give
artificial respiration. If breathing is
difficult, give oxygen. Get medical
attention.
Sodium Hydroxide
Potential Acute Health Effects:
Very hazardous in case of skin
contact (corrosive, irritant,
Ingestion: Do NOT induce
vomiting unless directed to do so
by medical personnel. Never give
anything by mouth to an
unconscious person. Loosen tight
clothing such as a collar, tie, belt
or waistband. Get medical
attention if symptoms appear.
Eye Contact: Check for and
remove any contact lenses. In
case of contact, immediately
permeator), of eye contact
(irritant, corrosive), of ingestion,
of inhalation. The amount of
tissue damage depends on
length of contact. Eye contact
can result in corneal damage or
blindness. Skin contact can
produce inflammation and
blistering. Inhalation of dust will
produce irritation to gastrointestinal or respiratory tract,
characterized by burning,
sneezing and coughing. Severe
over-exposure can produce lung
damage, choking,
unconsciousness or death.
Inflammation of the eye is
characterized by redness,
watering, and itching. Skin
inflammation is characterized by
itching, scaling, reddening, or,
occasionally, blistering.
Potential Chronic Health
Effects: CARCINOGENIC
EFFECTS: Not available.
MUTAGENIC EFFECTS:
Mutagenic for mammalian
somatic cells. TERATOGENIC
EFFECTS: Not available.
DEVELOPMENTAL TOXICITY:
Not available. The substance
may be toxic to mucous
membranes, upper respiratory
tract, skin, eyes. Repeated or
prolonged exposure to the
substance can produce target
organs damage. Repeated
exposure of the eyes to a low
level of dust can produce eye
irritation. Repeated skin exposure
can produce local skin
destruction, or dermatitis.
Repeated inhalation of dust can
produce varying degree of
respiratory irritation or lung
damage.
flush eyes with plenty of water for
at least 15 minutes. Cold water
may be used. Get medical
attention immediately.
Skin Contact: In case of contact,
immediately flush skin with plenty
of water for at least 15 minutes
while removing contaminated
clothing and shoes. Cover the
irritated skin with an emollient.
Cold water may be used.Wash
clothing before reuse. Thoroughly
clean shoes before reuse. Get
medical attention immediately.
Serious Skin Contact: Wash
with a disinfectant soap and
cover the contaminated skin with
an anti-bacterial cream. Seek
medical attention.
Inhalation: If inhaled, remove to
fresh air. If not breathing, give
artificial respiration. If breathing is
difficult, give oxygen. Get medical
attention immediately.
Serious Inhalation: Evacuate
the victim to a safe area as soon
as possible. Loosen tight clothing
such as a collar, tie, belt or
waistband. If breathing is difficult,
administer oxygen. If the victim is
not breathing, perform mouth-tomouth resuscitation. WARNING:
It may be hazardous to the
person providing aid to give
mouth-to-mouth resuscitation
when the inhaled material is
toxic, infectious or corrosive.
Seek immediate medical
attention.
Ingestion: Do NOT induce
vomiting unless directed to do so
by medical personnel. Never give
anything by mouth to an
unconscious person. If large
quantities of this material are
swallowed, call a physician
immediately. Loosen tight
clothing such as a collar, tie, belt
or waistband.
III.
Results
Table 2: Results from pH test on a 1wt% solution
Trial
Unknown sample
Calcium Nitrate
1
7.1
7.3
2
6.9
7.2
3
7.0
7.1
average
7.0
7.2
Table 3: Results observable properties
Trial
Unknown sample
Calcium Nitrate
Color of the sample
White
White
Color of the flame
Red
Red
Table 4: Results from solubility test on a solid sample
Trial
Unknown sample
Calcium Nitrate
Acetone
Soluble
Soluble
Ethanol
Partly soluble
Partly soluble
3M HCl
Soluble
Soluble
3M NaOH
Not Soluble
Not Soluble
Water
Soluble
Soluble
Table 5: Results from conductivity test on a 1wt% solution
Trial
Unknown sample
Calcium Nitrate
1
7.45
7.68
2
7.49
7.64
3
7.40
7.97
average
7.46
7.76
Table 6: Results from precipitation test on a 1wt% solution
Trial
1
Unknown sample
Unknown sample
Calcium
Calcium Nitrate
with silver nitrate
with barium chloride
Nitrate with
with barium
silver nitrate
chloride
No Precipitate
No Precipitate
No Precipitate
No Precipitate
2
No Precipitate
No Precipitate
No Precipitate
No Precipitate
3
No Precipitate
No Precipitate
No Precipitate
No Precipitate
Table 7: Results from gravimetric analysis
Trial
Unknown sample
Percent yield
Calcium Nitrate
Percent yield
1
0.13g
46%
0.01 g
3.57%
2
0.01g
3.57%
0.01g
3.57%
3
0.09g
32.14%
0.2g
71.43%
average
0.10g
27.24
0.07g
26.31
Calculations
a. Preparation of a 1wt% solution
10.52 gr of unknown in 100ml of water
10.53 gr of Calcium Nitrate in 100 ml of water
b. Average of 3 trials for “pick one test”
c. Theoretical yield from gravimetric analysis
𝐶𝑎𝑁𝑂3 + 𝑁𝑎2 𝐶𝑂3 = 𝐶𝑎𝐶𝑂3 + 𝑁𝑎𝑁𝑂3
Filter paper= 0.33 grams
Filter paper with precipitate= 0.43 grams
Precipitate weight= 0.1 grams
.3𝑔𝑟 𝐶𝑎𝑁𝑂
1 𝑚𝑜𝑙𝑒
Theoretical 1 𝑚𝑜𝑙𝑒 3 𝑥 105.98 𝑔𝑟 𝐶𝑎𝑁𝑂 𝑥 164.088𝑔𝑟 𝐶𝑎𝐶𝑂3= .28 gr CaCO3
3
Experimental 0.1g CaN03
d. Percent yield
[(Actual)/(theoretical)]x100
0.01g CaN03/( .28CaN03) = 46%
IV.
Discussion
Discuss all the test and from each one show what allows you to identify the unknown. (second
draft)
V.
Conclusion
Our results were pretty accurate and on point with the actual compound. Our unknown had the
same results as the Calcium Nitrate for all the solubility, flame, precipitate, conductivity, pH, and
gravimetric analysis test. Since all the test, except the gravitational analysis were accurate, we
could correctly assume that the unknown compound was Calcium Nitrate. The gravitational
analysis had a low percent yield because we made two mistakes. The first was a spill when
handling the liquids used. The second experimental error was that when we transferred the
solution with precipitate into the paper sheet we left some in the beaker because we did not
properly empty the solution into the paper by adding more water to get the precipitate of the
beaker. Besides this test, all the other tests were handed carefully for maxium accuracy and we
had good results. The easiest test to identify the compound was the Flame test and the physical
property test. We could immediately tell with the color, what substance we were dealing with.
VI.
Research connection
(second draft)
Find a research paper that you find interesting
What were they trying to do?
What was the main experiment?
What did they find?
References
ACS style
1 References in order of appearances, and use the number to cite them in the text
2 References in order of appearances, and use the number to cite them in the text
3 References in order of appearances, and use the number to cite them in the text
4 References in order of appearances, and use the number to cite them in the text
Lab 1 Report
Bucci Douglas
General Chemistry for Engineers Lab
I.
Introduction
The intent of the lab was to find out what salt our group was given by using multiple
different methods and experiments. We used several tests including, pH testing, a solubility
test, a conductivity test, a flame test, a precipitation test with Silver Nitrate and Barium
Chloride, and gravimetric analysis. Using the pH test allowed us to learn if the salt was acidic
or basic. The flame test allowed us to see the color the flame would be when burned and then
compare it to other flames which let us narrow down our choices. The solubility test allowed
us to find what liquids the salt was soluble in and compare it with other salts. The
conductivity test also allowed us to determine the conductivity and compare it with other
known samples. The precipitate test, allowed us to see how the salt precipitated and compare
that with other samples. For the gravimetric analysis, we were able to find the yield of the
mass of the salt used and find the mass of the salt. All these theories were proved through
multiple trials, where the average values from some of the test were used to find the result.
With all the results obtained from these experiments, we were able to compare our results
with the same experiments on other salts of known values. We narrowed down the possible
salts we could have been given, so that we were left with one. We then repeated all the
experiments with the salt we thought we had so that we could compare the results to see if
they line up, and to confirm that we had the correct salt.
II.
Procedures and methods
A. Preparation of a 1wt% solution for Unknown and “salt used”
B. pH Testing
C. Solubility test
D. Conductivity Testing
E. Flame Test
F. Precipitation test with Silver Nitrate and Barium Chloride
G. Preparation of solutions for gravimetric analysis
H. Gravimetric analysis
Table 1: Safety information
Chemical
Potential Danger
Precautions
Ethanol
Flammable
Wear gloves, lab coat, and
goggles
Acetone
Flammable, Irritant, Poisonous Wear gloves, lab coat, and
goggles
HCl
Corrosive, Can damage skin
Wear gloves, lab coat, and
goggles
NaOH
Corrosive, Can damage skin
Wear gloves, lab coat, and
goggles
Ca(NO3)2
Skin and Eye Irritant
Wear gloves, lab coat, and
goggles
Na2CO3
Skin and Eye Irritant
Wear gloves, lab coat, and
goggles
2NaNO3
Skin and Eye Irritant
Wear gloves, lab coat, and
goggles
CaCO3
Skin and Eye Irritant
Wear gloves, lab coat, and
goggles
III.
Results
Table 2: Results from pH test on a 1wt% solution
Trial
Unknown sample
Calcium Nitrate
1
7.3 pH
7.3 pH
2
7.1 pH
7.2 pH
3
7.3 pH
7.1 pH
average
7.23 pH
7.2 pH
Table 3: Results observable properties
Trial
Unknown sample
“salt used”
Color of the sample
White Crystal
White Crystal
Color of the flame
Red
Red
Table 4: Results from solubility test on a solid sample
Trial
Unknown sample
Calcium Nitrate
Acetone
Insoluble
Insoluble
Ethanol
Insoluble
Insoluble
3M HCl
Insoluble
Insoluble
3M NaOH
Soluble
Soluble
Water
Soluble
Soluble
Table 5: Results from conductivity test on a 1wt% solution
Trial
Unknown sample
Calcium Nitrate
1
4.41
5.64
2
5.06
8.67
3
9.42
12.09
average
6.29
8.80
4.91 Conductivity of Calcium Nitrate
Table 6: Results from precipitation test on a 1wt% solution
Trial
1
Unknown sample
Unknown sample
“salt used” with
“salt used” with
with silver nitrate
with barium chloride
silver nitrate
barium chloride
Precipitates
Doesn’t Precipitate
Precipitates
Doesn’t
Precipitate
2
Precipitates
Doesn’t Precipitate
Precipitates
Doesn’t
Precipitate
3
Precipitates
Doesn’t Precipitate
Precipitates
Doesn’t
Precipitate
Table 7: Results from gravimetric analysis
Trial
Unknown sample
Percent yield
Calcium Nitrate
Percent yield
1
0.32g
11.6%
0.33g
6.6%
2
0.34g
10.8%
0.32g
11.6%
3
0.32
13.3%
0.31g
9.9%
average
0.33g
11.9%
0.32g
9.4%
Calculations
a. Preparation of a 1wt% solution
a. 1g / 100 mL
b. Average of 3 trials for “pick one test”
a. (T1+T2+T3) / 3
c. Theoretical yield from gravimetric analysis
a. 250 mL / 2.5g = 30 mL / 0.3g is the amount of Na2CO3 in the solution
d. Percent yield
a. Percent Yield = (Actual Yield / Theoretical Yield) x 100%
IV.
Discussion
Discuss all the test and from each one show what allows you identify the unknown.
Finding the pH value for the salt allowed us to know what its range would be, if it was
acidic or basic. The flame test let us match the color of our salt when burned with other
salts to narrow down the list of salts. The solubility test helped us to find out which
liquids our salt was soluble in. The conductivity test let us determine the conductivity and
compare it with other known salts. The precipitate test, allowed us to see how the salt
precipitated. For the gravimetric analysis, we were able to find the yield of the mass of
the salt used and find the mass of the salt.
V.
Conclusion
What was your unknown salt a what was the most valuable test to identify it.
Our unknown salt was Calcium Nitrate. The most useful test we used to identify our salt
was the flame test because it gave us a clear visual representation.
VI.
Research connection
This research, scientists were trying to increase the salt tolerance of crops. The
scientist screened large numbers of crops for genotypes of salt tolerance to find salt
tolerant germplasm. They found that the trait of sodium exclusion has a high
heritability which will enable them to screen these crops faster and more precisely.
References
Rana Munns, Shazia Husain, Anna Rita Rivelli, Richard A. James, A. G. Tony Condon, Megan
P. Lindsay, Evans S. Lagudah, Daniel P. Schachtman, Ray A. Hare, Avenues for increasing salt
tolerance of crops, and the role of physiologically based selection traits [Online],
https://link.springer.com/chapter/10.1007/978-94-017-2789-1_7 (Accessed February 25, 2018)