Physical Science P2 1 September 2015 Preparatory Examination NSC-Grade 12-Memorandum. Basic Education

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1 Physical Science P 1 September 015 Preparatory Examination NSC-Grade 1-Memorandum Basic Education KwaZulu-Natal Department of Basic Education REPUBLIC OF SOUT AFRICA UMLAZI DISTRICT PYSICAL SCIENCES P MEMORANDUM (AMENDED) SEPTEMBER 015 PREPARATORY EXAMINATION NATIONAL SENIOR CERTIFICATE GRADE 1 MARKS : 150 N.B. This memorandum consists of 8 pages.

2 Physical Science P September 015 Preparatory Examination NSC-Grade 1-Memorandum QUESTION B () 1. B () 1.3 C () 1.4 C () 1.5 B () 1.6 A () 1.7 B () 1.8 D () 1.9 B () 1.10 A or B () QUESTION 10 x = [0] D (1).1. C (1).1.3 B (1) methylpent--yne IF 4 methylpent yne ½ ().. bromo-1-chloropropane IF bromo 1 chloropropane ½ () O C O C Marking criteria: Whole structure correct Only functional group correct ½ Notes: If two or more functional groups 0 Condensed or semi-structural formula Max 1 Molecular formula 0 ()

3 Physical Science P 3 September 015 Preparatory Examination NSC-Grade 1-Memorandum -.3. R O OR C O ().4 A, C (1).5 C n n (1) alcohols are flammable/propan-1-ol is flammable (1).6. esterification/condensation (1).6.3 propyl ethanoate ().6.4 Negative marking from Q.6.3 QUESTION 3 O Marking criteria: C C C O C C Whole structure correct Only functional group correct ½ () [19] 3.1 Boiling point (1) 3. The compound contains different functional groups and different types of intermolecular forces with varying degrees of strength The amount of energy required to overcome the intermolecular forces is therefore different (3) 3.3 The pressure exerted by a vapour in equilibrium with its solid/liquid phase. () 3.4 A A: In addition to London forces, there are two sites for hydrogen bonding. B: In addition to London forces, there is one site for hydrogen bonding. C: In addition to London forces, there are also dipole-dipole forces. The intermolecular forces in A are the strongest. (5) 3.5 A (1) [1]

4 Physical Science P 4 September 015 Preparatory Examination NSC-Grade 1-Memorandum QUESTION saturated - ANY ONE It has ONLY single bonds. It has single bonds between C atoms. It has no double OR triple bonds OR multiple bonds. Each C atom is bonded to four other atoms. () 4. hydrolysis (1) C O C C C C C Marking criteria: Whole structure correct Only functional group correct ½ Notes Accept -O as condensed in structural formula. If two or more functional groups 0 Condensed or semi-structural formula: Max. Molecular formula/molekulêre formule: 0 1 () 4.3. Concentrated sulphuric acid eat(strongly) () Elimination or dehydration (1) methylpent--ene Accept: 3-methyl--pentene () heat(strongly) If hyphens missing 4.4. elimination (1) [1] 1 (1)

5 Physical Science P 5 September 015 Preparatory Examination NSC-Grade 1-Memorandum QUESTION Negative marking decrease A gaseous product /carbon dioxide forms which escapes. (3) 5. To ensure a fair test OR To have ONLY ONE independent variable. (1) 5.3 CaCO 3 /calcium carbonate (1) 5.4 The reaction is complete /All the calcium carbonate has reacted. /The calcium carbonate is completely used up. (1) A () 5.5. B () C () 5.6 In experiment 4 the CaCO 3 was powder. Largest surface area Greater number of effective collisions occurred per unit time Greater gradient of graph/shorter time to reach completion. (3) QUESTION AB 3 AB B Initial quantity (mol) Change (mol) +4,4-4,4 -, ratio Quantity at equilibrium (mol) 8,4 1,6 0,8 Equilibrium concentration (mol.dm- 3 ) 4, 0,8 0,4 Divide by [15] K c = [ AB ] [ B ] [ AB ] 3 ( 0,8 ) ( 0,4) = 4, = 0,015 (8) Reading of number of initial number of moles correctly from the graph Using the correct ratio to calculate the change Correct calculation of the change Subtracting the change from the initial number of moles to get values at equilibrium Dividing by to get concentration at equilibrium Correct Kc expression(formulae in square brackets) Substitution of concentrations into Kc expression Correct answer: 0,015

6 - - Physical Science P 6 September 015 Preparatory Examination NSC-Grade 1-Memorandum 6. Temperature or Concentration () NOTE: QUESTIONS 6.3 TO 6.5 MUST BE MARKEDIN ACCORDANCE WIT ANSWER IN Temperature - Increased or Concentration of reactants - Increased (1) 6.4 According to LCP an increase in temperature favours the endothermic reaction. In this case the reverse reaction Number of mol of AB 3 increased. OR When the concentration of AB and B are increased,the reaction that favours the consumption of AB and B will be favoured. ence more AB 3 will be formed. (3) 6.5 Temperature : Decreases/Smaller than or Concentration: No change (1) 6.6 No change (1) [16] QUESTION An acid that contains protons ( + ) (1) 7.1. p = - log[ 3 O + ] 3,5 = - log[ 3 O + ] [ 3 O + ] = 3,16 x 10-4 mol.dm weaker than (1) The calculated concentration of the + ions is less than the concentration of the acid. The acid does not ionise completely while sulphuric ionises completely. () 7..1 pink (1) 7.. C 3 COO - + O C 3 COO + O - LS RS BAL (3) n(no 3 ) initial = cv = 0, x 0,05 = 0,005 mol (5 x 10-3 ) n(no 3 ) reacted with NaO = n(nao) = 0,1 x 0,01 = 0,001 mol (1 x 10-3 ) n(no 3 ) reacted with X CO 3 = 0,005-0,001 = 0,004 mol (4 x 10-3 ) (5) Positive marking from question n(x CO 3 ) = ½n(NO 3 ) = ½(0,004) = 0,00 mol ( x 10-3 ) n = 0,00 = m M 0,1 M M = 106 g.mol -1 () M(X) = (1 + 3(16)) = 3 g.mol -1

7 Physical Science P 7 September 015 Preparatory Examination NSC-Grade 1-Memorandum QUESTION complete the internal circuit or - maintain electrical neutrality (1) 8. - c(electrolyte) = 1 mol.dm 3 - T = 5 o C /98 K () 8.3 E o cell = E o cathode - E o anode = E o cathode - (-1,66) E o anode = 0,34 V X is Cu (5) (5) [0] 8.4 X + /Cu + is a stronger oxiding agent (than Al). Al is therefore oxidized. OR Al is the stronger reducing agent than Cu + and will reduce it to Cu (3) 8.5 decrease Cu + + e - Cu [Cu + ] decreases (4) Blue colour is due to Cu + ions [15] QUESTION electroplating (1) 9. cathode (1) 9.3 Ag + (1) 9.4 Ag + + e - Ag () 9.5 The rate at which Ag + is reduced at the cathode is equal to the rate at which the silver anode is oxidized to produce Ag + () [7]

8 Physical Science P 8 September 015 Preparatory Examination NSC-Grade 1-Memorandum QUESTION aber process (1) catalytic oxidation of ammonia (1) N 3 + 5O 4NO + 6 O LS RS BAL (3) oxygen (O ) (1) N 3 + SO 4 (N 4 ) SO 4 LS RS BAL (3) mass W : X : Y,4 : 0,8 : 4 Ratio,4 0,8 0,8 0,8 4 0,8 3 : 1 : Z = W : 3 X : 1 Y : 5,4 + 0, x 100 () = 36% (3) [14] TOTAL MARKS: [150]