NOUN Past Questions: CHM303 - Inorganic Chemistry III

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NOUN Past Questions: CHM303 - Inorganic Chemistry III

Postby Adebisi » Sat Feb 03, 2018 1:42 am

CHM 303 OCTOBER 2013 EXAMINATIONPAST QUESTION

NATIONAL OPEN UNIVERSITY OF NIGERIA 14/16 AHMADU BELLO WAY, VICTORIA ISLAND, LAGOS SCHOOL OF SCIENCE AND TECHNOLOGY OCTOBER 2013 EXAMINATION
Course Code: CHM 303
Course Title: INORGANIC CHEMISTRY III
Time: 2⅟2 Hours
INSTRUCTION: Answer any four Questions
1.
1. a) State the principal sources of Ne, Ar and Xe and how these elements can be obtained. (3 marks)
2. Why do the noble gases have the highest ionization energies compared to other elements

in their respective periods? (3 marks)
1. b) The noble gases are chemically unreactive but chemical reactivity of the noble gases increase as we go down the group from helium to radon. Explain. (5 marks)
1. State two uses of helium. (3 marks)

2.
1. a) Write an equation representing the reaction between xenon and fluorine at 700k, 6 atm. (3 marks)
2. What kind of compound is formed between quinol and the noble gases Ar, Kr or Xe under pressure

of 10-40 atmospheres. How do Ar, Kr or Xe bind to quinol to form this compound? (4 marks) b) i. Account for the structure of XeF4 according to the valence bond theory. (5 marks) ii. State 2 uses of hydrogen. (2 marks)
3.
1. a) What is the difference between beryllium oxide(BeO) and oxides of the other elements of

Group II. (4 marks)
1. Why is it that, unlike group I and II (with the exception of Be), Group IIIB elements are

essentially covalent or contain an appreciable amount of covalent character? (3 marks) b) i. Name the elements with which boron reacts, and the compounds formed. (4 marks) ii. How do the elements of Group IVA make more than four covalent bonds (carbon excluded)? (3 marks)
4.
1. a) What properties or characteristics of Group VA element make them exhibit properties of

non-metals? (3 marks)
1. What kind of oxides are formed when oxygen reacts with; (2 marks)

-Group I and II metals
-Sulphur and Phosphorus

1. b) Write chemical reactions to show the difference in the products formed when chlorine and

fluorine reacts with water. (2 marks)
1. Write the electronic configuration of the dipositive ion of Copper. (4 marks)
2. c) With the exception of Beryllium, Group IIA elements are good reducing agents and give ionic compound. Discuss (4 marks)

5.
1. a) State two characteristics of transition elements. (3 marks)
2. What is the main source of helium and how is it obtained from this source. (4 marks)
3. b) Discuss the trend in ionization energy going from the transition series SC to (7 marks)

p.t.o
6.
1. a) What do you understand by the term “lanthanide contraction”? (6 marks)
2. Identify the most stable state for lanthanides. (2 marks)
3. b) Why are the compounds of Sc3+, Ti4+ and Zn2+ white or colour (6 marks)

7.
1. a) What is a coordination compound? (3 marks)
2. Coordination compounds are said to be Lewis adduct. Explain. (5 marks)


3. b) What is Beneficiation of ores? (3 marks)
4. State the methods of beneficiation of ores. (3 marks)



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Re: NOUN Past Questions: CHM303 - Inorganic Chemistry III

Postby Adebisi » Sat Feb 03, 2018 1:44 am

CHM 303 OCTOBER/NOVEMBER 2014 EXAMINATION
NATIONAL OPEN UNIVERSITY OF NIGERIA
14–16 AHMADU BELLO WAY, VICTORIA ISLAND LAGOSSCHOOL OF SCIENCE AND TECHNOLOGY
OCTOBER/NOVEMBER 2014 EXAMINATION
CHM 303 – INORGANIC CHEMISTRY III Instruction- Answer any five questions Time-2½Hours
1ai. Briefly explain why XeF4 has square planar structure.2mks
1. Juxtapose why vander waals force between the noble gas atoms increase down the group. 3mks

1. b Write short notes on the following;

1. Lambda point. 2mks
2. Super conductivity. 2mks iii. Radon. 2mk

1. c. Using chemical equations show the formation of Xenon Tetra fluoride.3mks

2ai. Write balanced chemical equations to describe the reaction of potassium metal with:
(i) oxygen (ii) water (iii) chlorine (6 marks)

1. b. Work out the oxidation states of xenon in XeF4 and XeF6 (2mks)

1. c. Given below in Column I are the few expected compounds of noble gases. Write down in Column II the shapes of these compounds on the basis of VSEPR th (3mks)

Column I Column
(i) XeOF4 (ii)
(ii) XeO4 (iii)
(iii) XeF6 (iii)
1. d. State three State four uses of hydrogen. (3mks)

Question Three
3a. (i) List and describe the isotopes of hydrogen (3 marks)
(ii) What do you understand by the term ‘active hydrogen’? (2 marks)

1. b. Discuss the classification of ligands in coordination chemistry (6 marks) Question Four

4ai. What are β rays? (2 marks)
1. b. Discuss briefly the principles of the valence bond theory (6 marks)

1. c. Highlight the differences between the valence bond and molecular orbital theories (6marks)

Question Five
5a (i) What is the difference between gangue and slag? (4 mks)
(ii) Write balanced chemical equations to show how the flux forms the slag in an iron blast furnace. (4 mks)
(b) (i) Why is it necessary to concentrate the ores before extracting metals from them? (2 mks)
(ii) Describe the froth flotation process for the concentration of ores. (4mks)
Question Six
6ai. List and give the electronic configurations of the 3d transition elements (8 mks)
(b) What are rare earth elements? Why are they so called? (2 mks)
(c) (i) Identify the most common oxidation state for the lanthanides and the actinides (2 mks)
(ii) How is this oxidation state formed? (2 mks) Question Seven
7ai. How do the following properties vary in the transition elements? (6 marks) (i) Atomic size
(ii) Ionisation energy
(iii) Electronegativity
(b) Highlight four characteristics of transition metals (4 mks)
(c) (i) Explain briefly why CuSO4 is blue while ZnSO4 is white (2 marks) (ii) Predict the spin-only magnetic moment for: (2 marks)
Fe2+
Adebisi
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Re: NOUN Past Questions: CHM303 - Inorganic Chemistry III

Postby Adebisi » Sat Feb 03, 2018 1:48 am

NATIONAL OPEN UNIVERSITY OF NIGERIA
14/16 AHMADU BELLO WAY, VICTORIA ISLAND, LAGOS SCHOOL OF SCIENCE AND TECHNOLOGY
JUNE/JULY EXAMINATION
COURSE CODE: CHM303
COURSE TITLE: INORGANIC CHEMISTRY III
TIME ALLOWED: 21/2 Hours
INSTRUCTION: Answer any four questions
Q1
(a) (i) What is the difference between gangue and slag? (4 marks) (ii) Write balanced chemical equations to show how the flux forms the slag in an iron blast furnace. (4 marks)
(b) (i) Why is it necessary to concentrate the ores before extracting metals from them?
(3½ marks) (ii) Describe the froth flotation process for the concentration of ores. (4 marks)
(c) Why is carbon a preferred reducing agent in commercial metallurgy? (2 marks)
Q2
(a) Explain why there is a steady increase in boiling points from He to Rn (3 marks)
(b) Xenon reacts directly with fluorine on heating the gases in a nickel vessel. With the aid of chemical equations describe the reaction conditions and products of the reaction of xenon with fluorine. (3 marks)
(c) Work out the oxidation states of xenon in XeF2, XeF4 and XeF6. (6 marks) (d) (i) List and describe the isotopes of hydrogen (3 marks)
(ii) What do you understand by the term ‘active hydrogen’? (3 marks)
Q3
(a) List and give the electronic configurations of the 3d transition elements (10 marks) (b) What are rare earth elements? Why are they so called? (3 marks) (c) (i) Identify the most common oxidation state for the lanthanides and the actinides
(2 marks) (ii) How is this oxidation state formed? (3 marks)
Q4
(a) (i) Write the electronic configurations of helium, neon and argon. (3 marks)
(ii) What do you understand by the term ‘Lambda point’ in the study of helium? (2 marks)
(b) Given below in Column I are the few expected compounds of noble gases. Write down in
Column II the shapes of these compounds on the basis of VSEPR theory. (4 marks)
Column I Column II
(i) XeF4 (i) ………………………………… (ii) XeOF4 (ii) ……………………………… (iii) XeO4 (iii) ……………………………… (iv) XeF6 (iv) ………………………………
(c) State four uses of hydrogen gas. (4 marks)
(d) Write balanced chemical equations to describe the reaction of sodium metal with: (i) oxygen (ii) water (iii) chlorine (5 marks)
Q5
(a) How do the following properties vary in the transition elements? (6 marks) (i) Atomic size
(ii) Ionisation energy
(iii) Electronegativity
(b) Highlight five characteristics of transition metals (5 marks)
(c) (i) Explain briefly why CuSO4 is blue while ZnSO4 is white (3 marks) (ii) Predict the spin-only magnetic moment for: (4 marks)
Fe2+, Mn7+
Q6
(a) Discuss the classification of ligands in coordination chemistry (6 marks) (b) What are β rays? (2 marks)
(c) Discuss briefly the principles of the valence bond theory (5 marks)
(d) Highlight the differences between the valence bond and molecular orbital theories (5 marks)


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