a)(i) They are geometric/cis-trans isomers; (ii) Compound A: Trans 1, 2- dichloroethene, Compound B: Cis - 1,2- dichloroethene. (iii) The chemical properties will be the same (iv) because they both contain the same functional group; - they have same type of atoms connected in the same way
b)(1)- boiling takes place at a specific temperature; - boiling takes place throughout the liquid, - bubbles are formed vapour pressure is equal to atmospheric pressure (ii) I. It increases the boiling point of the water, ii. It lowers the boiling point of the water.
| BOILING | EVAPORATION |
| Occurs throughout the liquid | Occurs only at the surface of the liquid |
| Occurs at a particular constant temperature | Takes place at all temperatures |
| Has no cooling effect | Has a cooling effect |
| Exothermic | Endothermic |
| Occurs using external source of heat/not spontaneous | Occurs using internal energy/spontaneous |
| Bubbles are observed | Bubbles are not observed |
| Not affected by humidity | Affected by humidity |
| Fast process | Slow process |
| Unsaturated solution | Saturated solution |
| Can dissolve more solute at that temperature | Cannot dissolve any more solute at that temperature |
| Does not contain undissolved solute at that temperature | Contains undissolved solute at that temperature |
C. (ii) -increasing the temperature; - increasing the volume of solvent (iii.) - temperature; - volume of solvent; - nature of solute; - nature of solvent
D. (i) The amount of substance containing 6.02 x 10\(^23\) particles of that Substance/amount of substance containing as many particles as there are atoms in 12g of carbon 12.
(ii) n (HCI) = 25.0 x 10 dm3 x 0.1 moldm3, n (HCI) 2.5 x 10\(^-3\) mol.
From the equation of the reaction:
Mole of HCI = 0.025 x 0.1 = 0.0025
-->mol of MgO = 0.0025 / 2 = 0.00125mol
Molar mass of MgO = 24+ 16 =40
mass of MgO= 0.00125x 40 = 0.05g
(e) - are malleable,
-are ductile;
- are lustrous;
- have high melting point/boiling;
- have high tensile strength/hard Strong
-high density;
-solids at room temperature except mercury; -
good conductors of heat;
-good conductors of electricity: sonorous
