زهور الجوري
Member
السلام عليكم
ابي احد يحل الاسئلة
1. Preferably without consulting reference material, list the elements in Group 13/II and 14/1V and indicate:
a) The metals and nonmetals
b) Those that can crystallize in the daiamond structure
c) Those that form saline, metallic and metalloid carbides.
2. The lightest p-Plock elements often display different physical and chemical properties from the heavier members. Disuse the similarities and differences by comparison of:
a) The structure and electrical properties of (i) boron and aluminum and of (ii) carbon and silicon.
b) The physical properties and structures of the oxides of carbon and silicon
c) The physical properties and structures of the halides of boron and aluminum.
3. Describe the change in physical and chemical properties which may be observed in the elements C, Si, Ge, Sn and Pb. Give reasons for these changes.
4. Silicon and carbon are both members of group 14. However, silicon forms only single bonds with oxygen, while carbon forms double bonds with oxygen in many compounds. What accounts for this difference?
5. Example: Give the formula for the ion formed by each of the following:
chlorine: _______ calcium: _______ phosphorus: _______
sodium: _______ oxygen: _______ aluminum: _______
iodine: _______ lithium: _______ potassium: _______
6. Describe the trend in the difference of the atomic electronegativities of the atoms in these compounds as you go from left to right?
7. Because boron, B, has only three valence electrons, it has a tendency to form electron-deficient compounds. Show two different ways in which boron can attain an octet of shared electrons. Use only BCl3 and NH3
8. Write equation for each of the following reactions:
a) Reaction of diborane with ammonia
b) Reaction of diborane with HCl
c) Oxidation of Si by Chlorine
d) Diboron react with trimethylboron.
9. The electronic structure of C in its ground state 1s2 2s2 2px 2py. Why dose carbon usually form four single bonds not two?
10. What is graphite? Draw its structure and explain why its properties differ from those of diamond?
11. Answer of :
a) List ways in which CO can be made.
b) List ways in which CO2 can be made.
c) What is the main source of boron.
12. Choose the correct answer from among the following possibilities:
a) The most stable low-valent halide
GeCl2 SnCl2 PbCl2
Low valent compds that are increasing stable upon descending the group, Low valent MX2 which are readly hydrolysied and undergo coordination number expension to produce, for instance, SnCl62-, Pb Cl62-
b) A nonexistent halide:
SnCl4 PbCl4 PbF4
c) The main product on the reactions of lead with chlorine
PbCl4 PbCl2 PbOCl
13. Based on these properties and using the concept of diagonal relationships, answer the following questions.
a) What is the likely solubility of BeO in water?
b) Would you expect B(OH)3 to be acidic or basic or amphiprotic?
c) Would you expect molten Li2O to conduct an electrical current?
ابي احد يحل الاسئلة
1. Preferably without consulting reference material, list the elements in Group 13/II and 14/1V and indicate:
a) The metals and nonmetals
b) Those that can crystallize in the daiamond structure
c) Those that form saline, metallic and metalloid carbides.
2. The lightest p-Plock elements often display different physical and chemical properties from the heavier members. Disuse the similarities and differences by comparison of:
a) The structure and electrical properties of (i) boron and aluminum and of (ii) carbon and silicon.
b) The physical properties and structures of the oxides of carbon and silicon
c) The physical properties and structures of the halides of boron and aluminum.
3. Describe the change in physical and chemical properties which may be observed in the elements C, Si, Ge, Sn and Pb. Give reasons for these changes.
4. Silicon and carbon are both members of group 14. However, silicon forms only single bonds with oxygen, while carbon forms double bonds with oxygen in many compounds. What accounts for this difference?
5. Example: Give the formula for the ion formed by each of the following:
chlorine: _______ calcium: _______ phosphorus: _______
sodium: _______ oxygen: _______ aluminum: _______
iodine: _______ lithium: _______ potassium: _______
6. Describe the trend in the difference of the atomic electronegativities of the atoms in these compounds as you go from left to right?
7. Because boron, B, has only three valence electrons, it has a tendency to form electron-deficient compounds. Show two different ways in which boron can attain an octet of shared electrons. Use only BCl3 and NH3
8. Write equation for each of the following reactions:
a) Reaction of diborane with ammonia
b) Reaction of diborane with HCl
c) Oxidation of Si by Chlorine
d) Diboron react with trimethylboron.
9. The electronic structure of C in its ground state 1s2 2s2 2px 2py. Why dose carbon usually form four single bonds not two?
10. What is graphite? Draw its structure and explain why its properties differ from those of diamond?
11. Answer of :
a) List ways in which CO can be made.
b) List ways in which CO2 can be made.
c) What is the main source of boron.
12. Choose the correct answer from among the following possibilities:
a) The most stable low-valent halide
GeCl2 SnCl2 PbCl2
Low valent compds that are increasing stable upon descending the group, Low valent MX2 which are readly hydrolysied and undergo coordination number expension to produce, for instance, SnCl62-, Pb Cl62-
b) A nonexistent halide:
SnCl4 PbCl4 PbF4
c) The main product on the reactions of lead with chlorine
PbCl4 PbCl2 PbOCl
13. Based on these properties and using the concept of diagonal relationships, answer the following questions.
a) What is the likely solubility of BeO in water?
b) Would you expect B(OH)3 to be acidic or basic or amphiprotic?
c) Would you expect molten Li2O to conduct an electrical current?