Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
OBETA CHINONSO FAVOUR. 16/SCI14/018. GEOLOGY. CHM 221 ASSIGNMENT. 1. Thermal stability also describes, as defined by Schmidt (1928), [1] the stability of a water body and its resistance to mixing. This is the amount of work needed to transform the water body (e.g. a lake) to a uniform water density (reference: wikipedia.com). It is the decomposition of a compound on heating. The higher the temperature needed to decompose something, the more thermally stable it is (reference: thestudentroom.co.uk) 2. ππ(πΆπ)4 πΉπ(πΆπ) 5 πΆπ(πΆπ)6 Diagrams from Wikipedia and PubChem. 3. Metals can be extracted from their metal ores by: I. Electrolysis of their molten chlorides for metals like sodium, magnesium, calcium and potassium. ii. Reduction of oxides using carbons for metals like zinc, iron, tin, lead and copper. iii. Roasting of the ore by heating alone for metals like mercury, silver, gold and platinum. 4. The six properties of metal carbonyl are: i. They are fairly air stable. ii. Most of them obey the 18-electron rule and those that donβt are usually stored in nitrogen. iii. Their stability appeared to be kinetic or thermodynamic. iv. They are all toxic if swallowed. v. Most of them are soluble in organic solvent. vi. Most of them are crystalline solid except for such as Iron carbonyl πΉππΆπ5 , Osmium carbonyl ππ πΆπ5 which are liquid. 5. ππ24 π37 + πππ4 β β πππ3 + ππ2+ ππ24 π37 β πππ3 (oxidation) πππ4 ββ ππ2+ (reduction) 70π β + 35π»2 π + ππ24 π37 β 24πππ3 + 70π» + + 70π β (x5) 5π β + 8π» + + πππ4 β β ππ2+ + 4π»2 π (x70) 175π»2 π + 5πππ24 π37 β 120πππ3 + 350π» + + 350π β 350π β + 560π» + + 70πππ4 ββ 70ππ2+ + 280π»2 π 5ππ24 π37 + 70πππ4 β + 210π»+β 120πππ3 + 105π»2 π + 70ππ2+ 6a. ππ2 πΊπ π6 (+1)2 + 4(S) + 6(-2) =0 2 + 4S - 12 = 0 4S = +12 - 2 4S = +10 S = 10/4 S = +2.5 S β +3. 6b. π½π2 V + (-2)2 = 0 Vβ4=0 V = +4. 6c. π·2 π7 2(P) + (-2)7 = 0 2P β 14 = 0 2P = +14 P = 14/2 P = +7. 8. The periodic table is a table of the chemical elements arranged in order of atomic numbers, usually in rows so that elements with similar atomic structure (and hence similar chemical properties) appear in vertical columns. It is the tabular arrangement of the chemical elements ordered by their atomic numbers (number of protons), electron configurations and recurring chemical properties. 9. The atomic radius is the distance from the atomic nucleus to the outermost stable electron orbital in an atom that is at equilibrium. The atomic radii tend to decrease across a period from left to right. The atomic radius usually increases while going down a group due to the addition of a new energy level (shell). The ionization energy is the minimum amount of energy required to remove one electron from each atom in a mole of atoms in the gaseous state. There will be an increase of ionization energy from left to right of a given period and a decrease from top to bottom. The electron affinity of an atom can be described either as the energy gained by an atom when an electron is added to it, or conversely as the energy required to detach an electron from a singly charged anion. It increases from left to right across the period. Electronegativity is a measure of the ability of an atom or molecule to attract pairs of electrons in the context of a chemical bond. The type of bond formed is largely determined by the difference in electronegativity between the atoms involved, using the Pauling scale. Trend-wise, as one moves from left to right across a period in the periodic table, the electronegativity increases due to the stronger attraction that the atoms obtain as the nuclear charge increases. Moving down in a group, the electronegativity decreases due to the longer distance between the nucleus and the valence electron shell, thereby decreasing the attraction, making the atom have less of an attraction for electrons or protons. 10. Electronic configuration is the distribution of electrons of an atom or molecule (or other physical structure) in atomic or molecular orbitals. 11. The electronic configurations of the following elements are: i. Ca : 1π 2 2π 2 2π6 3π 2 3π6 4π 2 ii. Al : 1π 2 2π 2 2π6 3π 2 3π1 iii. P : 1π 2 2π 2 2π6 3π 2 3π3