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*THE COMPLETE 2017 CHEMISTRY THEORY ANSWERS*
*🤝ELITE TEAM ALIVE💫*
*VERIFIED AND CONFIRMED OBJECTIVES*
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1D 2D 3B 4B 5C 6D 7C 8A 9C 10D 11A 12D 13B 14C 15C 16B 17D 18A 19C 20D 21B 22D 23A 24C 25A 26B 27C 28B 29D 30B 31A 32B 33B 34C 35C 36A 37D 38D 39D 40D 41B 42D 43B 44A 45B 46A 47C 48A 49A 50C
*Section A Question 1*
*===================*
*1a*. Graham's Law of diffusion states that the rate of diffusion of a gas is inversely proportional to the square root of its density.
*1b* (i) Change in Concentration
(ii)Changes in Pressure and Volume
1(c) 3Cl₂ + 6KOH → KClO₃ + 5KCl + 3H₂O
*1d* (i)H₂SO₃ - sulfurous acid
(ii)H₃PO₄ - Phosphoric acid.
*1e* (i)Increase in temperature.
(ii)concentration of a dissolved reactant.
(iii)Catalyst
*1f* (i)Variable oxidation states
(ii)Formation of colored compounds
(iii)Good conductors of electricity and heat.
*1g* Given :
V₁ = 153 cm³
T₁ = 21+273 = 294k
T₂ = 45+273=318k
_According to Charles' Law equation:_
153 × 318
V₂ = ------------------
294
∴ V₂ = 165.5 cm³
_Volume of the gas is *165.5 cm³*_
*h* (i) A Normal salt is formed when all the hydrogen ions(H+) of an acid, have been replaced by metal ions or by the ammonium ions(NH4+).
(ii)Calcium carbonate
*(i)* I-Alloys contain atoms of different sizes.
II-They are a mixture or metallic solid solution composed of two or more elements.
*j* (i) Dibasic
(ii) H⁺ and SO₃⁻²
*SECTION B*
*ANSWER THREE (3) QUESTIONS ONLY*
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*QUESTION 2*
*2a)* Boyle's law states that at constant temperature for a fixed mass, the absolute pressure and the volume of a gas are inversely proportional.
*2aii* In Relation with kinetic theory and ideal gases. Boyle's law states that at constant temperature for a fixed mass, the absolute pressure and the volume of a gas are inversely proportional. The law can also be stated in a slightly different manner, that the product of absolute pressure and volume is always constant.
*2bi* *solubility curve* :a graphic representation of the variation with changing temperature of the solubility of a given substance in a given solvent.
*2biii*(i) temperature (ii) pressure.
*2ci )*Efflorescence is a crystaline deposit on surfaces of masonry, stucco or concrete. It is whitish in appearance, and is sometimes referred to as "whiskers".
*2cii* Deliquescence, the process by which a substance absorbs moisture from the atmosphere until it dissolves in the absorbed water and forms a solution.
*============================*
*Question 3*
*Q3*(a)(i) Electrolytes are substances in either the liquid or molten state that can allow current to pass through them with decomposition
*(ii)* Volume of Cl2=?, Mass of K=7.8g, Quantity of electricity, Q=96500*7.8/39=193000C
Anode reaction: 2Cl^-> Cl2 +2e
Therefore, Volume of Cl2=193000*22.4/2*96500=432320/193000=2.24dm3
*(b)*(i) 1 The rate of the forward reaction must be equal to the rate of the backward reaction 2 The overall heat change must be zero (ii) I The position of equilibrium will shifts to the right II The position will shifts to the right because the concentration of the reactant has been increased
(c) *(i)* CH3CH2CH=CH2 *(ii)* CH3CH2CH3 and CH3CH2CH2CH3 *(iii)*
CH3CH2CH2COOH
*(iv)*answers in *c(ii)*
*(d)* The trend in the boiling points of the substances is as the result of the stronger covalent bonds and higher molecular mass
*====================================*
*Question 4*
*Q4(a)(i)* A chemical industry is one that uses chemistry to make chemicals from other chemical substances or raw materials. (ii) 1 Chemical industries are sources of environmental pollution 2 Some Chemical industries lead to land degradation (iii) 1 Fertilizer industry 2 Metallurgy industry
*(b)(i)* 1 Sulphuric acid 2 Sodium chloride (ii) NaCl + H2SO4> NaHSO4 + HCl (iii) Concentrated sulphuric acid (iv) Displacement of air(Downward delivery of the gas) (v) The gas is denser than air (vi) 1. Its solution reacts with alkaline solution to form salt and water 2 It reacts with ammonia in the presence of moist to form White fumes of ammonium chloride
*(c)(i)*Acidity of the halides increases down the group because going down the group electrons are easily lost
*(ii)* The bond in potassium trioxocarbonate(IV) is stronger than the one in lithium trioxocarbonate(IV)
*Q4(d)(i)* The gas produced in the electrolysis of molten alumina is oxygen which is not toxic or dangerous to life forms. On the other hand, toxic chlorine gas is produced in the electrolysis of molten sodium chloride
*(ii)*Na2CO3 is more suitable for the preparation of a standard alkaline solution because it is not deliquescent and does not attract glass
D biology
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