WASSCE HEADQUARTERS 💯

BECE 2024 SCHOOL UPDATE

•BECE Results Release Date: 14th October, 2024)

•School Reopening: October 28th, 2024

•Reporting Date for BECE 2024 candidates is 21st November, 2024

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Congratulations everyone 🎉 let's hope for the best 👌 👍......

All
Pens down !🎉🍾.....

*Q7 solution*

a) In an equilibrium reaction , some reactants remain unconverted and this leads to lower yields of desired products.

b) It can cause damage to equipment and increase cost of maintenance.

Ca(HCO₃)₂ can decompose upon heating to form calcium carbonate (CaCO₃) which forms scales and block pipes and equipment. This scale buildup reduces efficiency and causes damage to equipment.

c) I ) Constant pressure

ii) crushing limestone increases the surface area and exposes more molecules. There is an increase in the number of effective collisions between the reacting molecules and hence there is an increase in the rate of decomposition


iii) Equilibrium position of a reversible reactions refers to the relative concentration of reactants and products in a reversible reaction when the forward and backward reactions occur at the same rate.

iv) The enthalpy change for the forward reaction is equal in magnitude but opposite in sign to the enthalpy change in the backward reaction. That is , if the foward reaction is exothermic , the backward reaction is endothermic



e i) Allotropy refers to the existence of an element in two or more different forms in the same physical state, with each form having distinct physical and chemical properties

ii) 1. Diamond
2. Graphite

*Q6 solution*

1a) Isomerism is the occurrence of two or more compounds with the same molecular formula but different molecular structures.

b) Condensation polymerization
Addition polymerization

C) Covalent bond is a bond formed from the sharing of electron pair equally between two atoms in which each atom contributes an electron.
A dative covalent bond on the other hand is a bond formed by sharing of a pair of electrons in which both electrons are donated by only one of the bonding atoms.


d i ) Graham’s law of diffusion states that at constant temperature and pressure , the rate of diffusion of a gas is inversely proportional to the square root of its density.

ii)



e) 1. Relative position of the ions in the electrochemical series
2. Nature of electrodes
3. ⁠Relative concentration of the ions in the electrolyte


g) Fluorine and Chlorine are in the same group and generally, electron affinity decreases down a group due to increased atomic radius and inter-electronic repulsion. Fluorine has an unexpectedly lower E.A compared to Chlorine because Fluorine has a very small size which tends to create electron-electron repulsion between its existing electrons and any incoming electrons. The electron has to be forced in and this reduces the overall energy released in fluorine.


h) 1. Add water to the mixture. Sodium chloride will dissolve, while sand will not.
2. Filter the mixture to separate the undissolved sand from the sodium chloride solution.
3. Heat the filtrate to evaporate the water, leaving behind solid sodium chloride.

I) A concentrated solution of a base contains a higher amount of the base in a smaller volume of solution whiles a dilute solution contains a smaller amount of the base in higher volume of solution

J) Potassium Chlorate
Hydrogen peroxide
Sodium Nitrate

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