CHEM OBJ 1-10- DABDADABDA 11-20- EEDAEADDBB 21-30- AACBDEABCC 31-40- DBCCAAAACA 41-50- EACEEEEAAA 51-60- EEBCABBACA 1a) Atomicity is the number of atoms in a molecule of an element 1aii) Mass number of an element is the sum of the proton number and the neutron number 1aiii) Isotopy is the existence of atom of the same element that have the same atomic number but different mass number 1bi) The reaction is a displacement reaction because Zinc will displaced hydrogen from hydrochloric acid because it is above hydrogen in the activity series. There is an effervescence & hydrogen gas is given off the gas is collected over water because it is insoluble in water Zn + Hcl ----------- Zncl2 + H20 1bii) It is used in filling ballons because it has a low density * it is used in hardening Fat and oils in the manufacture of margine and other solid fats * it is used in the manufacture of ammonia in the harber process 1c) Molar mass of HNO3 = 1 + 14 + (16)3 = 63g/mol % of oxygen = (16)3/63 x 100% = 76.19% 1d) * copper * iron * Tin * Aluminium 1e) * Sodiumtetrahy-droxozinate(ii) --------- Na2Zn(OH)4 * sodiumoxonitrate(iii) --------- NaNo2 1eii) Used in soap making * used to soften hard water * used as fertilizer * sodium chloride is used as preservative for meat and fish 2a) cassiterite 2aii) Sn02 + 2c(s) -------------> Sn(s) + 2CO(g) 2aiii) * Ethanoic acid from vinegars * Tartaric acid from grapes * Lactic acid from milk * Amino acid from protein 2bi) * used in making cooking utensils * used in making alloy * used in making overhead electric cable 2bii) * Increasing the concentration * Increasing the temperature of a system * Increasing the surface area of magnesium 2biii) Mg + 2HCL -------------> Mgcl + H2 2c) * Downward delivery or upward displacement of air * hydrogen chloride gas * ammonia gas * solubility 2di) The heat involved when one mole of substance is burned completely in oxygen under standard condition (2dii) DG = DH - TDS = -710 - (300 x 0.15) = -755kg/mol (2diii) * It alters the rate of chemical reactions * it is specific in action * it cannot start a reactions * it has no effect on the equilibrium position of a reversible reaction 3a) * Double decomposition reaction * Redox reaction * Displacement reaction 3bi). (I) R - OH (ii) R - COOH (iii) R - C=O-R Where R= alkyl group = CnH2n+1 3bii) CnH2n-2 3biii) * All members can be prepared by the same general method * They have similar chemical properties * They share same general molecular formula * Each successive member differ by -CH2 3ci) * Hydrogentetraoxosulphate(vi)acid [ H2So4 ] * Hydrogentrioxonitrate(v)acid [ HNO3 ] * Hydrochloric acid [ HCL ] 3cii) Ethanol , * propan-2-ol 3d) 19A »»» 1s2, 2s2, 2p6, 3s2, 3p6, 4s1 9B »»» 1s2, 2s2, 2p5 3dii) Electovalent bond 3diii) Soluble in water * Insolube in organic solvent * Conduct electricity in aqueous 3e) diff in solubility from 100oc to 15oc = 39.8 - 35.9= 3.9g I.E solute deposited on cooling, on cooling from 100oc to 15oc, Mass involved at 100oc= 39.8g + 1000g of water = 1039.8g Mass involved at 15oc= 35.9g + 1000g of water = 1035.9g Ie 1039.8g of saturated solution deposited 3.9g of solute. Ie 80g of saturated solution deposite -------- 3.9 x 80/1039.8= 0.30g of water 4a) Allotropy is the existence in the same physical state of two or more structural forms of the same element 4aii) Rhombic sulphur * Monoclinic sulphur * Amorphous sulphur * Plastic sulphur 4b) cracking process * C8H18 - octane * It reduce knocking 4c) Addition polymerization * Condensation polymerization 4cii) hardness of water ia a suitation whereby water does not lather easily with soap 4d) octane salting is a figure indicating the antiknock properties of a fuel based on a comparison with a mixture of isoctane & heptane 4dii) Cracking: this is whereby complex molecule are broken down into simpler molecule. While, Reforming: is the process used to convest molecule having low octane rating into high octane liquid product 4diii) Cu2+ + 2e- ----------> Cu 2F ------------> 1 mole 2 x 96500c ----------> 1 mole 482.5c -------------> M/64 2 x 96500 x M/64=482.5 M= 0.16g 4e) chlorofluoro carbon * Carbon(ii)oxide * Sulphur(iv)oxide 5a) An aerosol is a colloid of fine solid particles or liquid droplets in air or another gas * An emulsion is a collided solution of liquid in liquid 5aii) Haze. (ii) Milk 5aiii) Harber process * Hydrogenation process 5b) Fractional distillation 5bii) High inflammable * insoluble in water * Good organic solvent 5c) used in manufacture of HCL * for water purification * dyeing industry * manufacture of organic substance 5cii) SOLID: molecule are fixed and tightly packed * It has a definite shape * they are compacted together LIQUID: molecule are loose * it takes shape of the container * it moves freely 5d) HCL + NAOH ——–> NACL + H20 Ca=? , Va=20.30cm ie 20.30 x 10^-3dm3, Vb= 25 x 10^-3 , Cb=0.1 Ca = 0.1 x 25×10^-3/20.30 x 10^-3 Ca = 0.123mol/dm3 6a) standard heat of naturalization is the heat change when one mole of hydrogen ion from acid react with one mole of hydroxide ion from an alkaline to form one mole of water under standard conditions 6aii) Conc H2S04 , conc HCL , Aluminiumtetraoxosulphate(vi) 6aiii) Temperature , Amount of solute in solvent 6b) As fire extinguisher * in photosynthesis process * in the solvay process * As coolant in nuclear reactions
Posted on: Mon, 16 Jun 2014 09:41:49 +0000
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