Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Chemistry 2000 lab exam > Steps A - D potassium trioxalato ferrate tri hydrate > Flashcards

Steps A - D potassium trioxalato ferrate tri hydrate Flashcards

(106 cards)

Start Studying
1
Q

what are the three phases of a synthesis

A
  1. reaction
  2. workup
  3. characterization
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

describe the three phases of a synthesis

A

reaction
- identifying what parameters need to meet to have a successful experiment (like what are the reactants, what solvent is needed?)

workup
- some way to isolate the desired product from biproducts present

characterization
- qualitative and quantitative analysis to determine if we have made the correct product and HOW much

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is the limiting reagent in

2 H2 + O2 —> 2 H2O

A

oxygen is the limiting reagent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the chemical formula for ferrous oxalate hydrate

A

FeC2O4 x H2O

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what colour is ferrous oxalate hydrate

A

yellow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is an intermediate to the complex salt

A

ferrous oxalate hydrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the formula for potassium trioxalato ferrate (iii) trihydrate

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

proper technique for diluting 18 M H2SO4 to 100 ml 3M H2SO4

A

v1c1 = v2c2
(0.1L)(3M) = x(18M)
V2 = 0.017 ml

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

is oxalic acid a liquid or solid under normal lab conditions

A

solid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

is this reaction a reduction or oxidation

A

reduction (Mn)4 is gaining electrons)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how to calculate theoretical yield

A

actual yield from experiment / theoretical yield from product produced based on limiting reagent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the end point colour change of the permanganate-oxalate reaction

A

dark purple to light pink

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

why is potassium permanganate handled carefully

A

will leave brown spots on clothes or skin AND can irritate skin and eyes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is the catalyst used in the permanganate-oxalate reaction

A

manganous ion (Mn2+)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are the colour of the crystals in the final product

A

green

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

why did we analyze the final crystals

A

to determine the percent composition of each element in the crystals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what was the first step of preparing the Ferrous Oxalate (PART A)

A

quantitatively transferring the ferrous ammonium sulfate to a beaker charged with 25 ml of warm water and acidified with 20 drops of 3 M H2So4

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is the formula for Ferrous Ammonium Sulfate

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

how was the mass of Ferrous Ammonium Sulfate used determined (PART A)

A

after transferring to the prepared beaker the vial was rinsed with small amount of RO water and dumped into beaker

AFTER the vial was washed with acetone to evaporate the water and weighted

Subtract the vial with crystals from vial without

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

how was oxalic acid prepared (PART A)

A

2.5 grams of the oxalic acid with 25 ml of RO water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what do oxalic acid crystals need to fully dissolve (PART A)

A

gentle heating

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

where was the oxalic acid added (PART A)

A

to the Ferrous Ammonium solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

what was done once the oxalic acid was added to the ferrous ammonium solution (PART A)

A

the combined solution was brought to a gentle boil while stirring CONTINUOUSLY

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what happens as the oxalic acid and ferrous ammonium solution was heated (PART A)

A

the precipitate at the bottom goes from a dark orange colour to more yellow as more ferrous oxalic forms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
describe the steps of part A when the Buchner funnel was used
the clear supernatant liquid was decanted with a vacuum filtration system the precipitate was washed with 25 ml of hot water and decanted again (discarding the liquid but keeping the solid) third wash again with 25mL of hot RO water and transfer the ENTIRE precipitate to the filter paper in the Buchner funnel final rinse with 25 ml of acetone
26
what was the LAST step in the preparation of the ferrous oxalate intermediate (PART A)
transferring the dry yellow crystals to a weighted 250 ml beaker and letting sit for the week
27
what was the objective of part A
aims to synthesize the intermediate compound (ferrous oxalate dihydrate) by heated combination of ferrous ammonium sulfate hexahydrate and oxalic acid dihydrate undergoing filtration with a vacuum apparatus
28
is potassium permanganate an oxidizing agent or reducing agent
oxidizing agent
29
is potassium permanganate reduced or oxidized in a reaction
reduced
30
what is the formula for potassium permanganate
KMnO4
31
what does potassium permanganate look liked reduced in BASIC OR NEUTRAL conditions
mixture of products results including SOLID MnO2 and green Manganate ion MNO4
32
what does potassium permanganate look like reduced in ACDICI conditions (half reaction)
33
what was the molarity of the potassium permanganate solution produced
0.02 M
34
what are safety precautions for bisulfite cleaning solution
irritant to the respiratory tract, eyes, mucous membranes and skin
35
how can the bisulfite cleaning solution be discarded
down the sink with lots of water
36
how much potassium permanganate was initially weighed to form 0.02 M solution
1.2 to 1.4 grams
37
what colour is potassium permanganate
black powder
38
what was the weighted potassium permanganate added to
a 600 ml beaker with 300 to 323 ml of water
39
what was done once the potassium permanganate was added to the water
heated to a gentle rolling boil
40
what was done once the potassium permanganate solution was heated to a gentle boil (FIRST TIME)
let sit with watch glass over and cool for FIVE minutes
41
what was done after the potassium permanganate solution was cooled
reheated to a gentle boil
42
what was done with the potassium permanganate solution after both boils and cooled
filtered through a funnel with glass wool positioned over a clean plastic bottle
43
how was a bottle cleaned for the potassium permanganate solution
10 ml of the bisulfite cleaning solution was poured into the bottle and let clean the bottle AND CAP before rinsing with RO water
44
what was observed after the potassium permanganate was added to the water
the solution changed colour to a dark purple
45
is the MNO4-/C2O4-2 reaction slow or fast at room temp
SLOW
46
what was unique about the MNO4-/C2O4-2 titration
was carried out at elevated temps
47
what increases the rate of the MNO4-/C2O4-2 titration
the production of the catalyst Mn2+
48
what is the MNO4-/C2O4-2 titration reaction called
autocatalytic
49
what is an autocatalytic reaction
a chemical reaction where one of the products of the reaction acts as a catalyst to speed up the reaction and produce more of itself
50
what was added to the three Erlenmeyer flasks for the MNO4-/C2O4-2 titration
1. 0.18 to o0.22 g of sodium oxalate 2. 60 ml of RO water 3. 10 ml of 3 M H2SO4
51
what is the formula for sodium oxalate
Na2C2O4
52
how was each MNO4-/C2O4-2 titration carried out
1, heat the contents of the flask between 80 to 90 degrees 2. titrate the solution with KMNO4 solution
53
describe the first few drops in the MNO4-/C2O4-2 titration
very SLOW to initiate the reaction
54
what is the overall equation for the MNO4-/C2O4-2 titration
55
potassium permanganate formula
56
potassium permanganate
57
sodium bisulfite
58
sodium bisulfite
59
ferrous ammonium sulfate hexahydrate
60
ferrous ammonium sulfate hexahydrate
61
oxalic acid dihydrate
62
oxalic acid dihydrate
63
ferrous oxalate dihydrate
64
ferrous oxalate dihydrate
65
balanced reduction reaction for MNO4-/C2O4-2 titration
66
balanced oxidation reaction for MNO4-/C2O4-2 titration
67
how to find molarity of KMnO4 for one trial of MNO4-/C2O4-2 titration
68
what was done with the ferrous oxalate intermediate after it was dry
it was suspended in 30 ml of warm solution containing 3.5 g potassium oxalate
69
what colour was the suspension after the ferrous oxalate intermediate was added to the potassium oxalate solution
dark orange/ rust colour
70
how much H2O2 was measured out
10 ml into a graduated cylinder
71
what were the steps and precautions taken when adding H2O2 to the solution with the ferrous oxalate intermediate and potassium oxalate solution
in an ICE BATH the H2O2 was added in SMALL increments (1ml increments) while stirring
72
what was the result after H2O2 was added to the solution with ferrous oxalate intermediate and potassium oxalate solution
brown slushy solid
73
what was the resulting brown slush made of (after H2O2 added to solution with the ferrous oxalate intermediate and potassium oxalate solution)
Fe(OH)3
74
how was oxalic acid made for the second step of complex salt synthesis
1g oxalic acid to 10 ml of wate r
75
what were the steps for adding the oxalic acid to the solution of ferrous oxalate intermediate, potassium oxalate solution and H2O2
add the first 7 ml and then heat to a gentle boil before adding the last 3 ml with an eye dropper
76
what was done after the solution with the ferrous oxalate intermediate, potassium oxalate, oxalic acid, and h2o2 was heated together
filter through Buchner funnel
77
after filtering through Buchner filter what was done to the second intermediate product of complex salt
15 ml of 95% ethanol
78
how were the complex salt crystals harvested
filter with suction and wash crystals with 20 ml of EQUI-VOLUME ethanol and water AFTER, rinse with 20 ml of acetone
79
what happens to the final product as it is exposed to light
soon become covered with yellow powder (ferrous oxalate)
80
is H2O2 an oxidizing agent or reducing agent
oxidizing agent
81
is H2SO4 a strong or weak acid
strong
82
safety precautions for H2SO4
corrosive and irritant to skin and causes severe burns
83
safety precautions for H2O2
corrosive irritant to skin, eyes, mucous membranes
84
objective for the second step in complex salt synthesis
take the previously produced ferrous oxalate dihydrate and using potassium oxalate and hydrogen peroxide form the final product potassium trioxalato ferrate (iii) trihydrate by the process of filtering through a Buchner funnel. AFTER the product has been allowed to sit in the dark the complex salt will form crystals due to recrystallization
85
what colour did the brown sludge turn after the oxalic acid was added
green
86
potassium oxalate monohydrate formula
87
potassium oxalate monohydrate
88
ethanol formula
89
ethanol
90
acetone
91
potassium trioxalato ferrate (iii) trihydrate
92
balanced equation for complex salt
93
limiting reagent in the equation for complex salt
FeC2O4 x 2 H2O (ferrous oxalate dihydrate)
94
how was percent water found in the green crystals (steps in experiment)
1. weight 0.7 to 0.8 of the complex salt into evaporating dish (pre-weighted) 2. place dish in the oven at 120 for 45 mins 3. let cool 4. weight to a constant mass
95
how was percent oxalate found in the green crystals (steps in experiment)
1. weight out three samples (0.18 to 0.22 g ) of complex salt into 3 Erlenmeyer flasks 2. add 60 ml H2o and 10 ml 3 M H2SO4 to each flask 3. heat ONE sample to 80 - 90 degrees before completing titration with KMnO4 until faint pink seen
96
when is the titration with KMnO4 done (end point)
when a faint pink colour is seen
97
how was percent iron found in the green crystals (steps in experiment)
1. add 3ml 18 M H2SO4 to dried crystals in evaporating dish and cover with watch glass 2. heat the contents in the dish for several mins on hot plate 3. cool the contents in the fume hood 4. pour ferric sulfate into Erlenmeyer flask and add 25 ml of RO water 5. heat Erlenmeyer flask contents to boil 6. add small proportions of zinc until the pale yellow solution turns clear 7. filter through Whatman paper into clean flask and titrate with KMnO4
98
when can zinc be added to the ferric sulfate
when the solution had turned a pale yellow colour from the cloudy solution
99
what is the objective of the final stage in this synthesis
determine whether we have produced the correct product (potassium trioxalato ferrate (III) trihydrate) after the 2 previous phases and to determine we have the correct yield of the product
100
what is the half reaction for Fe3+
101
what is the half reaction for Zn
102
what is the reaction between Zn and Fe3+
103
what is the half reaction for MnO4-
104
what is the half reaction for Fe2+
105
what is the reaction between MNO4- and Fe2+
106
how to calculate percent deviation

Chemistry 2000 lab exam (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions