Which of the following is the safest way to pick up broken glassware?

using a paper towel or dust pan/broom

What happens when a drop of NaOH is added to an acetic acid/sodium acetate buffered solution?

The acetic acid neutralizes the NaOH, causing a very small change in pH.

reaction rate would stay the same

When the temperature of a reaction is increased, the rate of the reaction is affected because _______ is increased.

the average kinetic energy of reactant molecules

Large spills of a hazardous liquid on the clothes and skin:

Take off all the affected clothes immediately, run to the nearest shower

In the “Spectrophotometric Determination of Iron” lab, why is o-phenanthroline used in the experiment?

To form a colorful complex with iron

toward the products, toward the right

Whenever you conduct chemistry experiments, which of the following is proper attire?

closed-toed shoes and long pants

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Chem 132 Lab Exam II

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1
The main reaction studied is:3I⁻_(aq)+ H₂O_2(aq)+ 2H⁺_(aq)----> I₃⁻ _(aq)+ 2 H₂O_(l) Why was starch added?
to cause a color change
to act as a catalyst
to make the reaction safer
to speed up the reaction
2
Given the following reaction:
4th order
1st order
0 order
2nd order
3
You should never return dispensed chemicals or waste to the original container from which they came.
True
False
4
Which of the following is NOT an example of an ionic compound?
CaCO3
MgSO4
C6H12O6
NaCl
5
If you mix 5.0 mL of 0.250 M NaCH3CO2 (aq) with 10. mL of water, calculate the new molar concentration of sodium acetate
.17 M
3.8 M
.25 M
0.083 M
6
See Image:
increase
decrease
remain the same
7
See Image:
1.3 M
.29 M
.034 M
.39 M
8
Which of the following is the safest way to pick up broken glassware?
bare hands
move it around with your feet
using a paper towel or dust pan/broom
9
Potassium nitrate, KNO3, is a/n _____________.
neutral salt
basic salt
acidic salt
strong base
10
Explain why a buffered solution experiences only a small change in pH when a strong acid is added.
DIY
Wrong
11
See Image:
WRONG
WRONG
DIY
12
What happens when a drop of NaOH is added to an acetic acid/sodium acetate buffered solution?
The acetic acid neutralizes the NaOH, causing a very small change in pH.
The acetic acid reacts with the NaOH, causing a large change in pH.
The sodium acetate reacts with the NaOH, causing a large change in pH.
The sodium acetate neutralizes the NaOH, causing a very small change in pH.
13
You remove some reagent from the reagent bottle in lab and place it in a clean beaker.What to do with leftover?
back in the bottle
dispose as waste
leave it for the next lab
14
What is the name of the this piece of glassware?
test tube
buret
graduated cylinder
Erlenmeyer flask
15
Can the following piece of glassware be used to measure accurate volumes?
no
yes
16
According to the following graph, what is the wavelength, λ, of maximum absorbance for the substance measured?
0.92
524 nm
490 nm
560 nm
17
See image:
reaction rate would stay the same
reaction rate would be doubled
reaction rate would be quadrupled
reaction rate would be halved
18
When the temperature of a reaction is increased, the rate of the reaction is affected because _______ is increased.
the average kinetic energy of reactant molecules
the amount of water
the concentration of reactant molecules
the amount of catalyst
19
Large spills of a hazardous liquid on the clothes and skin:
Take off all the affected clothes immediately, run to the nearest shower
Can usually be wiped off without a serious problem
Require immediate use of the safety shower
20
Hydrofluoric acid, HF, is a weak acid. Write the ionization reaction for hydrofluoric acid.
wrong
DIY
21
See Image:
0.0002
0.00045
0.03
0.05
22
See Image:
[FeSCN2+] will increase
[FeSCN2+] will decrease
[FeSCN2+] will remain unchanged
23
Before absorbance, a blank must be run to zero the spect... at a specific wavelength using the pure solvent in cuvette.
False
True
24
See Image:
toward products, right side
would not affect the equilibrium; no change
toward reactants, left side
25
See Image:
2.1 g
820 g
.50 g
.00030 g
26
See Image:
0.6 M NH3 / 0.3 M NH4+
0.8 M NH3 / 0.4 M NH4+
v0.4 M NH3 / 0.2 M NH4+
1 M NH3 / 0.5 M NH4+
27
Calculate the [H3O+] in a 0.50 M HClO aqueous solution.HClO (aq) Ka = 3.5 x 10-8
1.8 x 10-8 M
0.50 M
1.3 x 10-4 M
0.30 M
28
See Image:
Endothermic
cannot determine
Exothermic
29
Consider the Reaction:
3.8
60.
130
0.017
30
In the “Spectrophotometric Determination of Iron” lab, why is o-phenanthroline used in the experiment?
To form a colorful complex with iron
To reduce the iron(III) ion to iron (II) ion
To zero the spectrophotometer
To dilute the solution
31
The scale for each axis should be so that the curve will extend nearly the full length of the sheet in both directions.
True
False
32
In the Beer's Law equation, what does A stand for? A = εbc
Absorbance
The substance concentration
temperature
light
33
How many H atoms are ionizable on the following compound?
5
2
1
3
34
See Image
0.0025 mg/mL
0.0050 mg/mL
0.050 mg/mL
0.50 mg/mL
35
A takes 30 min to completely react and B to takes 15 min to react, which has the FASTER (larger) reaction rate?
Reaction B
cannot determine
Reaction A
36
Which one of the following is the correct equation for Beer's law?
c = A ε b
A = ε c
c = Ab
A = ε b c
37
See Image:
toward the products, toward the right
the reaction will remain unchanged, no shift
toward the reactants, toward the left
38
Determine the [H3O+] in a 0.25 M HCl aqueous solution.
.25 M
.50 M
.60 M
1.0 M
39
See Image
absorbance will decrease
absorbance will increase
absorbance will remain constant
40
Safety in the laboratory is
The responsibility of the professor only
The responsibility of the student only
A shared responsibility
41
Every time you change the spectrophotometer to a new wavelength, you should re-zero using the pure solvent in a cuvette.
False
True
42
Given the following reaction:
4th order
1st order
2nd order
3rd order
43
Plot some data using Excel, the equation for the trendline is: y = -4.5x + 12.2 what is the slope of trendline?
-4.5
+4.5
2.71
12.2
44
See Image
Strong Electrolyte
Non electrolyte
Weak electrolyte
45
Which of the following mixtures can act as a buffered solution?Only one answer is correct.
H3PO4 and H2PO4-
H3PO4 and HCl
H3PO4 and PO43-
HCl and NaOH
46
See Image:
20%
10%
0.5%
5.0%
47
See Image:
acid solution
base solution
neutral solution
buffer solution
48
See Image:
Think
Wrong
Wrong
49
Whenever you conduct chemistry experiments, which of the following is proper attire?
all of these are acceptable
high-heels and a skirt
closed-toed shoes and long pants
sandals and shorts
50
In the laboratory, you can leave a drinking water bottle on your bench while doing experiments as long as it is closed.
True
False
51
See Image
rate = k [R] [D2]2
rate = k [R]2 [D2]
rate = k [R]2 [D2]2
rate = k [R] [D2]
52
If an acid is spilled on your hand, the best course of action is to:
Wipe your hand with a paper towel
Run to the lab shower and take a soak
Wash the acid off with running water in a sink
53
see below
0.00030 M/min
0.20 M/min
0.30 M/min
0.10 M/min
54
In the Beer's law equation, what does "c" stand for?
wavelength of light
molar absorptivity
the concentration of absorbing species
absorbance
55
What is the slope of the trendline in the following graph?
0.5167 atm/min
0.9630 atm/min
1.038 atm/min
0.4976 atm/min
56
Which of the following can have an effect on the rate of a reaction?
temperature of reaction
addition of catalyst
reactant concentration
All of the options listed are correct.
57
If the equilibrium constant is 3.0 x 10^-6, at equilibrium the expected concentration of FeSCN2+ will be relatively
small
large
cannot determine
58
Using the following graph, does absorbance, A, vary linearly with respect to wavelength?
yes
cannot determine
no
59
Given the following rate law, what is the overall order of reaction for the reaction it represents? rate = k [A]³ [B]
2nd order
3rd order
4th order
1st order
60
If a reaction is first order, which type of graph for that reaction will produce a linear function?
1/[R] vs time
ln [R] vs time
temperature vs time
[R] vs time
61
If you spill on the lab bench some 1 M HNO3 , what is the proper way to clean up the spill?
wipe up with a wet paper towel
sprinkle with baking soda and wipe up with a paper towel
wipe up with a paper towel
put it in the glass waster container
62
If the following reaction was at equilibrium, what would the color of the reaction be after adding excess water?
green
blue
cannot determine
colorless
63
See Image
Wrong
DIY
64
In the following graph, the vapor pressure varies linearly with respect to temperature.
True
False
65
The x- and y-axes are labeled with the name of the variable plotted, but the unit is not necessary.
False
True
66
Phenolphthalein, a pH indicator, is added to the titration before the procedure begins. Why?
To provide a basic solution for the titration reaction
To keep the solution from evaporating while the titration takes place
To create a color change when the titration endpoint is reached
Because the phenolphthalein is a standardized solution
67
See Image:
dark purple, pH 10 or greater
red, pH 4 or less
blue, pH 8
green, pH 7
68
When the nonelectrolyte ethanol, CH3CH2OH , is added to water, what are the actual species in the solution?
C+, H2, O-, H2O
CH3CH2OH, H2O
CH3CH2OH, H2O
CH3CH2+, OH-, H2O
69
See Image
Think
Wrong
Wrong
70
The pH of a 0.10 M solution of unknown weak acid HA is 3.50. Determine the value of the Ka for this acid.
2.9 x 10-2
1.0 x 10-6
3.2 x 104
3.2 x 10-4
71
When the strong electrolyte, HCl, is added to water, what are the actual species in the solution?
H3O+, Cl-, HCl, H2O
Cl-, HCl, H2O
HCl, H2O
H3O+, Cl-, H2O
72
A reaction where the molecule absorbs light at the wavelength. Assume Beer's law what is 1/2-life of 1st order reaction?
5 min
10 min
.5 min
4 min
73
It is recommended that you have a fire extinguisher in your home while performing these experiments.
True
False
74
A nonelectrolyte ______________.
Conducts NO electricity
Conducts a LITTLE Electricity
Conducts A LOT of electricity
Always contains color in solution
75
According to Beer's law, concentration of a substance that absorbs light is __ to absorbance of light by that substance.
inversely proportional
not related
directly proportional
logarithmically related
76
See Image:
toward products, right side
would not affect the equilibrium; no change
toward reactants, left side
77
See Image:
0.003 mg/mL
0.001 mg/mL
1.1 mg/mL
0.0025 mg/mL
78
The glass volumetric pipets can be put directly into the reagent bottles of stock solution.
False
True
79
If you use a 1mL volumetric pipet to deliver liquid, how many sig figs are recorded for that volume measurement?
2
4
3
1
80
For the following reaction, which is the correct equilibrium constant expression?
Kc= ([FeSCN2+])/ ([Fe3+][SCN-])
Kc= [FeSCN2+]
Kc= ([Fe3+][SCN-])/ [FeSCN2+]
Kc= ([FeSCN2+])/ [SCN-]
81
It is possible for a reaction to reach equil... and still have a higher reactant conc... than product conc....
False
True
82
What is wrong with the following plot?
The title does not accurately display the variable being plotted.
A straight line was used to connect the dots rather than a line of best fit
Units are not given for the y axis.
Minor gridlines are not provided.
83
Which correctly represents the acid ionization constant expression for the weak acid hydrogen sulfate ion, HSO₄^-?
Ka= [SO42-][H3O+]
Ka= ([SO42-][H3O+]) / [HSO4-]
Ka= ([SO42-][H3O+]) / ([HSO4-][H2O])
Ka= [H3O4-] /([SO42-][H3O+])
84
See Image:
left side, reactant side
heat should be on both sides of the equation
right side, product side
heat should not be written in the equation
85
Which will have a higher conductivity, 0.5 M HBr (aq) or 0.5 M HF (aq)?
O.5 M HBr
They shall be equal
0.5 M HF
86
When the rate of the reverse reaction is equal to the rate of the forward reaction, what state has the reaction reached?
this is not possible for a reaction
solid state
irreversible reaction
dynamic equilibrium
87
Which of the following acids has a Ka value greater than 1? (there is only one correct answer)
HCl
HF
HClO
HCH3CO2
88
Buffer capacity is the amount of strong acid/base that can be added to a buffer solution w/out a significant pH change.
True
False
89
A solution has a pH of 1.25. What is the equilibrium hydronium ion concentration of this solution?
18 M
0.25 M
1.25 M
0.056 M
90
Why do we run a solvent blank in the spectrophotometer before running samples?
Wrong
Wrong
Wrong
Think it through
91
See Image:
HNO2 (aq) + H2O(l) (double arrow)H2NO2+ (aq) + OH-(aq)
KNO2 (aq) + KOH(aq) (double arrow) K+ (aq) + HNO2 (aq)
HNO2 (aq) + OH- (aq) -------> NO2- (aq) + H2O(l)
HNO2 (aq) + H2O(l) (double arrow) NO2- (aq) + H3O+ (aq)
92
See Image:
Add base, purple
Add base, yellow
Add Acid, yellow
Add Acid, purple
93
Does a strong acid or weak acid have the greater reactivity? Also, explain why this is true.
wrong
Think
94
For the following reaction, the reaction is 1st order in PH3. Which represents the correct way to write the rate law?
k [PH3]
rate = k
rate = k [PH3]4
rate = k [PH3]
95
If you have a "standardized" solution of potassium hydroxide, what does that tell you about the solution?
The conc... of the sol... has been precisely determined through titration.
All solutions that are part of titrations are "standardized solutions."
The pH of the solution is precisely known.
The solution is a buffered solution.
96
See Image
K+
HCH3O2
H2O
CH3CO2-
97
See Image:
Fe3+
Cl-
both Fe3+ and Cl-
O2-
98
A solution has a pH of 3.00. When it is diluted to half the concentration, the pH is 3.30. This solution is a _______.
Strong Base
Weak acid
Weak Base
Strong Acid
99
The K_a of HCO₃^- is 4.8 x 10^-11.Choose the correct chemical reaction that this K_a represents.
HCO3- (aq) + H2O(l) (double arrow) CO32- (aq) + OH- (aq)
HCO3- (aq) + H2O(l) (double arrow) CO32- (aq) + H3O+(aq)
HCO3- (aq) + H2O(l) (double arrow) H2CO3 (aq) + H3O+(aq)
HCO3- (aq) + H2O(l) (double arrow) H2CO3 (aq) + OH- (aq)
100
See Image
wrong
wrong
Think

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