(a) Molecular formula gives the actual number of each kind of atom in one molecule while structural formula is a graphical representation of a molecule of a compound which shows how the atoms are linked/bonded together OR Molecular formula gives the total number of atoms of each element in one molecule of a compound. while structural formula shows li arrangements/relative position of atoms/atoms and bonds in one molecule of a compound.
(b) Factors that Determine the ionization Energy of an Atom:- Atomic radius/size of atom Nuclear charge.
- Shielding effect/screening effect.
- Electron configuration,-Penetration effect.
(c) Conditions Necessary for the Establishment of a Chemical Equilibrium - The rates of the forward and backward reactions must be equal.
- \(\bigtriangleup\)G must be zero.
- The temperature must be constant
- System must be dynamic/ all reactant and product must be present.
- System must be closed.
(d) Consider the following table: | Element | A | B | C |
| Ionization energy KJ mol\(^{-1}\) | 619 | 518 | 594 |
(i) Element B
Reason: Element B has the lowest ionization energy/ it loses electrons most easily.
(e)
Graham's Law of Diffusion: Graham's law of diffusion states that the rate of diffusion of gas at the same temperature and pressure is inversely proportional to the square root of its vapor density/molar mass
(f)i. Salts that is/are readily soluble in water: - Mg(NO\(_{3}\))\(_{2}\), Na\(_{2}\)SO\(_{4}\)
(ii) Insoluble in Water - CaCO\(_{3}\)
(g) Product classification as addition polymer or condensation polymer: (i) Protein - Condensation.
(ii) Perspex - Addition.
(iii) Nylon - Condensation.
(h) Define Atomic Radius:- lt is defined as half the distance between the nuclei of any two close atoms in a molecule/or is a measure of the size of its atoms, the mean distance from the center of the nucleus to the boundary of the surrounding shells of electrons.
(i) Why ethanol has a higher boiling point than propane even though they both have comparable molar mass: - The intermolecular forces in ethanol are hydrogen bonds which are stronger than the van der Waal's forces in propane.
(j) Three Significance of pH Value in Everyday Life: - Digestion of food.
- Determination of
pH of soil/used in agriculture.
- Important role in the survival of animals (self-defense) existence of living beings.
- pH change as the cause of tooth decay.
- Treatment of water for public supply.
- reatment of industrial efluent/ liquid waste.
- ln pharmaceuticals.
- In medicine (to determine pH of body fluid/urine /blood).
