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Transcript
Inorganic Chemistry - Problem Drill 01: Introduction and Applications
Question No. 1 of 10
Instructions: (1) Read the problem statement and answer choices carefully, (2) Work the problems on paper as needed, (3)
Pick the answer, and (4) Review the core concept tutorial as needed.
Which of the following element belongs to the p-block of the periodic table?
Question
A. Ti
B. Ca
C. E
D. C
E. Li
A. Incorrect!
Titanium is a transition metal which belongs to the d-block (4s23d2 electron configuration).
B. Incorrect!
Ca is an alkaline earth metal which belongs to the s-block (s2 electron configuration).
C. Incorrect!
Europium belongs to the f-block and is classified as a lanthanide.
Feedback
D. Correct!
Carbon has a s2p2 electron configuration which belongs to the p-block.
E. Incorrect!
Lithium is an alkali metal which belongs to the s-block (s1 electron configuration).
Correct answer: (D) Carbon
The elements can be divided into 4 sections based on their valence electron configurations.
Solution
s-block:
p-block:
d-block:
f-block:
ns1ns2 (Alkali and alkaline earth metals)
ns2npx: x = 1-6 (Main group elements)
ns2(n-1)dx: x = 1-10 (Transition metals)
ns2(n-2)fx: f = 1-14 (Lanthanides and actinides)
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Question No. 2 of 10
Instructions: (1) Read the problem statement and answer choices carefully, (2) Work the problems on paper as needed, (3)
Pick the answer, and (4) Review the core concept tutorial as needed.
Which of the following is not an example of an organometallic compound?
Question
A. Fe(C5H5)2
B. K2[PtCl4]
C. Al(C2H5)3
D. Cr(CO)6
E. Si(CH3)4
A. Incorrect!
This is an example of an organometallic compound known as ferrocene. A compound is classified as
organometallic if it contains at least one metal-C bond.
B. Correct!
This is not an example of an organometallic compound. A compound is classified as organometallic if it
contains at least one metal-C bond.
C. Incorrect!
This is an example of an organometallic compound. A compound is classified as organometallic if it
contains at least one metal-C bond.
Feedback
D. Incorrect!
This is an example of an organometallic compound. A compound is classified as organometallic if it
contains at least one metal-C bond.
E. Incorrect!
This is an example of an organometallic compound. A compound is classified as organometallic if it
contains at least one metal-C bond.
Correct Answer: (B) K2[PtCl4]
Solution
This is not an example of an organometallic compound. A compound is classified as organometallic if it
contains at least one metal-C bond. All other listed compounds have a metal-carbon bond. The term
organometallic can also be applied to metalloids.
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Question No. 3 of 10
Instructions: (1) Read the problem statement and answer choices carefully, (2) Work the problems on paper as needed, (3)
Pick the answer, and (4) Review the core concept tutorial as needed.
What is the coordination and oxidation number for the complex [Co(NH3)4Cl2]+ ?
Question
A. 6, +1
B. 4, +3
C. 6, +3
D. 6, +2
E. 6, +4
A. Incorrect!
The coordination number is the number of ligands directly attached to the metal in the coordination
sphere. Ammonia is a neutral ligand.
B. Incorrect!
The coordination number is the number of ligands directly attached to the metal in the coordination
sphere. Ammonia is a neutral ligand.
C. Correct!
The coordination number is the number of ligands directly attached to the metal in the coordination
sphere. Four ammine (NH3) and 2 chloro (Cl-). Ligands are coordinated to the Co metal.
Feedback
D. Incorrect!
The coordination number is the number of ligands directly attached to the metal in the coordination
sphere. Ammonia is a neutral ligand.
E. Incorrect!
The coordination number is the number of ligands directly attached to the metal in the coordination
sphere. Ammonia is a neutral ligand.
Correct answer: (C) 6, +3
The coordination number is the number of ligands directly attached to the metal in the coordination
sphere. Four ammine (NH3) and 2 chloro (Cl-). Ligands are coordinated to the Co metal.
Solution
Co is in the +3 oxidation state since the overall charge of the complex is +1 and ammonia is a neutral
ligand.
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Question No. 4 of 10
Instructions: (1) Read the problem statement and answer choices carefully, (2) Work the problems on paper as needed, (3)
Pick the answer, and (4) Review the core concept tutorial as needed.
Which of the following is not an example of a homogeneous catalyst?
Question
A.
B.
C.
D.
E.
Hydrogenation of ethene over a Ni catalyst
Conversion of methanol to acetic acid using [RhI2(CO)2]- catalyst
Reaction of an alkene with CO, H2 in the presence of a Co complex to form an aldehyde
Decomposition of hydrogen peroxide catalyzed by organometallic complexes
Hydrogenation of alkenes using the Wilkinson’s catalyst
A. Correct!
This is an example of a heterogeneous catalyst. The catalyst is a solid and the reactants are in a different
phase (gas).
B. Incorrect!
This is an example of a homogeneous catalyst. Both reactants and catalyst are in same phase (liquid).
This process is known as the Monsanto acetic acid synthesis.
C. Incorrect!
This is an example of a homogeneous catalyst. Both reactants and catalyst are in same phase (liquid).
This process is known as the hydroformylation reaction.
Feedback
D. Incorrect!
This is an example of a homogeneous catalyst. Both reactants and catalyst are in same phase (liquid).
Catalysis by organometallic complexes are associated with homogeneous systems.
E. Incorrect!
Wilkinsons’s catalyst is rhodium complex [RhCl(PPh3)3]. The catalyst and the reactants are present in a
homogeneous solution.
Correct answer: (A) Hydrogenation of ethene over a Ni catalyst
This is an example of a heterogeneous catalyst. The catalyst is a solid and the reactants are in a different
phase (gas). The reactants are very often activated to react by chemisorption onto the catalytic surface.
Solution
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Question No. 5 of 10
Instructions: (1) Read the problem statement and answer choices carefully, (2) Work the problems on paper as needed, (3)
Pick the answer, and (4) Review the core concept tutorial as needed.
Which of the following is NOT TURE regarding zeolites?
Question
A. Zeolites are aluminosilicate minerals.
B. Zeolites have a porous structure.
C. Zeolites can selectively sort ions or molecules based on their sizes.
D. Zeolites can be used as water softeners.
E. Zeolites are not applicable as catalyst.
A. Incorrect!
This is a true statement. Zeolites have a three dimensional aluminosilicate framework.
B. Incorrect!
This is a true statement. The three dimensional aluminosilicate framework consist of pores, which can
accommodate different ions or molecules.
C. Incorrect!
This is a true statement. The three dimensional aluminosilicate framework consist of pores, which can
accommodate different ions or molecules.
Feedback
D. Incorrect!
This is a true statement. The three dimensional aluminosilicate framework consist of pores, which can
accommodate different ions or molecules. The hard ions in water (Ca2+, Mg2+) can be exchanged with
softer ions.
E. Correct!
This is a false statement. Zeolites can be used as a catalyst for selective isomerization and alkylation of
aromatics.
Correct answer: (E) Zeolites are not applicable as catalyst.
This is a false statement. Zeolites can be used as a catalyst to selective isomerization and alkylation of
aromatics.
Solution
Zeolites have a three dimensional aluminosilicate framework. The three dimensional aluminosilicate
framework consist of pores, which can accommodate different ions or molecules.
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Question No. 6 of 10
Instructions: (1) Read the problem statement and answer choices carefully, (2) Work the problems on paper as needed, (3)
Pick the answer, and (4) Review the core concept tutorial as needed.
Which physical method is used determine elemental composition in surface of material?
Question
A. IR spectroscopy
B. X-ray photoelectron spectroscopy
C. ESR (EPR)
D. X-ray crystallography
E. Multinuclear NMR
A. Incorrect!
IR spectroscopy along with Raman spectroscopy can be used to identify specific bonds present in
compounds or surfaces. However, does not give information of elemental composition.
B. Correct!
XPS (also known as ESCA) can detect composition of elements in the first 1-12 nm of the surface.
XPS uses X-rays to eject electrons from the sample. The energy of the ejected electron corresponds to its
binding energy in atomic electronic structure.
C. Incorrect!
Electron spin resonance spectroscopy is used to detect the number and spin state of unpaired electrons
presented in a compound.
Feedback
D. Incorrect!
X-ray crystallography is used to determine complete molecular structure (including bond lenghths and
bond angles) of a crystalline substance.
E. Incorrect!
NMR spectroscopy can be used to determine molecular structure and mechanisms of inorganic reactions.
Correct answer: (B) X-ray photoelectron spectroscopy
Solution
XPS (also known as ESCA) can detect composition of elements in the first 1-12 nm of the surface.
XPS uses X-rays to eject electrons from the sample. The energy of the ejected electron corresponds to its
binding energy in the atomic electronic structure. The number of electrons ejected is related to the
amount of element present in sample volume irradiated with X-rays.
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Question No. 7 of 10
Instructions: (1) Read the problem statement and answer choices carefully, (2) Work the problems on paper as needed, (3)
Pick the answer, and (4) Review the core concept tutorial as needed.
What is the role of iron in hemoglobin?
Question
A.
B.
C.
D.
E.
Transport iron
Store iron
Bind and transport oxygen
Catalyze reduction of oxygen
Transport carbon dioxide from the lungs
A. Incorrect!
Hemoglobin is an oxygen transport protein.
B. Incorrect!
Hemoglobin is an oxygen transport protein.
C. Correct!
Hemoglobin is an oxygen transport protein. The iron is coordinated to a heme structure.
Feedback
D. Incorrect!
Hemoglobin is an oxygen transport protein.
E. Incorrect!
Hemoglobin is an oxygen transport protein.
Correct answer: (C) Bind and transport oxygen.
Hemoglobin is an oxygen transport protein. The globular protein structure allows strong binding of
oxygen. The coordination chemistry of iron plays a major role in the binding process.
Solution
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Question No. 8 of 10
Instructions: (1) Read the problem statement and answer choices carefully, (2) Work the problems on paper as needed, (3)
Pick the answer, and (4) Review the core concept tutorial as needed.
Which of the following is not true regarding nanomaterials?
A. Nanomaterials show different properties than bulk materials.
B. Quantum dot is an example of a semiconductor nanoparticle.
C. The energy (color) of emitted light can be tuned by varying the size of the quantum dot.
D. Nanomaterials are micrometer sized particles.
E. Certain allotropes of C have nanostructures.
Question
A. Incorrect!
This is a true statement. Nanomaterials show quantum mechanical effects due to their smaller
dimensions. This results in unique electrical, optical and catalytic properties.
B. Incorrect!
This is a true statement. Quantum dots are semiconductor particles whose diameter is less than 1/10 th
of a micrometer. Examples include CdS, CdTe and metal oxides.
C. Incorrect!
This is a true statement. The band gap of the semiconductor particles are altered as the size of the
particle is changes. This results in different emission energies.
Feedback
D. Correct!
This is a false statement. Nanomaterials have dimensions less than 0.1 micrometer (1-100 nm)
E. Incorrect!
This is a true statement. Fullerene is an allotrope of C and is an example of a nanomaterial. The
fullerenes can be synthesized with cage or channel like pores. C60 (buckminsterfullerene) is an example of
a fullerene which is shaped like a ball.
Correct answer: (D) Nanomaterials are micrometer sized particles.
Solution
This is a false statement. Nanomaterials have dimensions less than 0.1 micrometer (1-100 nm)
Nanomaterials show quantum mechanical effects due to their smaller dimensions. This results in unique
electrical, optical and catalytic properties.
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Question No. 9 of 10
Instructions: (1) Read the problem statement and answer choices carefully, (2) Work the problems on paper as needed, (3)
Pick the answer, and (4) Review the core concept tutorial as needed.
Which of the following is not true regarding the periodic table?
Question
A. Halogens belong to Group 18 according to the modern IUPAC system.
B. Halogens belong to Group VIIA according to the CAS system.
C. Boron belongs to Group IIIB in the old IUPAC nomenclature.
D. Alkali metals belong to Group IA according to the CAS nomenclature.
E. All lanthanides have similar properties.
A. Correct!
This is a false statement. Halogens belong to Group 17. Group 18 belongs to the noble gases.
B. Incorrect!
This is true statement. The CAS system uses the letter A for main group elements. The group number
corresponds to the number of valence electrons.
C. Incorrect!
This is a true statement. The old IUPAC system uses the letter A for the left side of the periodic table and
the letter B for the right side of the periodic table.
Feedback
D. Incorrect!
This is a true statement. The CAS system uses the letter A for main group elements. The group number
corresponds to the number of valence electrons.
E. Incorrect!
This is a true statement. Lanthanides belong to the f-block and show minor variations in properties.
Correct answer: (A) Halogens belong to Group 18 according to the modern IUPAC system.
This is a false statement. Halogens belong to group 17. Group 18 belongs to the noble gases. According
to the modern IUPAC system the group numbers are labelled in increasing order 1-18.
Solution
The CAS system uses the letter A for main group elements. The group number corresponds to the
number of valence electrons.
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Question No. 10 of 10
Instructions: (1) Read the problem statement and answer choices carefully, (2) Work the problems on paper as needed, (3)
Pick the answer, and (4) Review the core concept tutorial as needed.
Which of the following compounds is colored?
A. CaCl2
B. Al(C2H5)3
C. Sn(CH3)4
D. CH3COOH
E. K4[Fe(CN)6]
Question
A. Incorrect!
Ionic compounds formed between main group elements does not absorb in the visible region.
B. Incorrect!
Al is a main group element. Transition metal complexes are generally colored due to electrons in partially
filled d-orbitals.
C. Incorrect!
Sn is a main group element. Transition metal complexes are generally colored due to electrons in partially
filled d-orbitals.
Feedback
D. Incorrect!
Acetic acid is an aliphatic organic compound, which are generally colorless.
E. Correct!
This is a transition metal complex. Transition metal complexes are generally colored due to electrons in
partially filled d-orbitals.
Correct answer: (E) K4[Fe(CN)6]
This is a transition metal complex. Transition metal complexes are generally colored due to electrons in
partially filled d-orbitals.
Solution
The degenerate d-orbitals are split into two sets of different energy in the presence of ligands. The
separation energy of the two sets match the visible region of the electromagnetic spectrum. Electron in
the lower levels can be promoted to the higher levels by absorption of visible light.
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