CLASS TEST GRADE 11. PHYSICAL SCIENCES: CHEMISTRY Test 7: Chemical systems

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1 CLASS TEST GRADE PHYSICAL SCIENCES: CHEMISTRY Test 7: Chemical systems MARKS: 45 TIME: hour INSTRUCTIONS AND INFORMATION. Answer ALL the questions. 2. You may use non-programmable calculators. 3. You may use appropriate mathematical instruments. 4. Number the answers correctly according to the numbering system used in this question paper. 5. Data sheets are attached for your use. 6. Wherever motivation, discussion, et cetera is required, write brief answers.

2 SECTION A QUESTION : ONE-WORD ANSWERS Give ONE word or term for each of the following descriptions. Write only the word or term next to the question number (..2).. The method used to separate iron ore from sand and dirt. ().2 The technique used to separate the different components of crude oil. () [2] QUESTION 2: FALSE STATEMENTS Correct the following FALSE statements. Write the correct statement next to the question number (2. 2.2). 2. Carbon dioxide is the major pollutant gas during the roasting of iron. (2) 2.2 Plants absorb phosphorus in the form of fluorapatite. (2) [4] QUESTION 3: MULTIPLE-CHOICE QUESTIONS Choose the correct answer to the following questions. Write only the letter (A D) next to the question number (3. 3.2). 3. Which one of the following is not a renewable source of energy? A solar energy B coal C hydroelectric power D wave energy (2) 3.2 The primary pollutant in photochemical smog is A SO 2 B CO 2 C NO D CFC (2) [4] TOTAL SECTION A: 0 Maskew Miller Longman, Focus on Physical Sciences Grade Test 7: Chemical systems Page 2 of 7

3 SECTION B INSTRUCTIONS AND INFORMATION. The formulae and substitutions must be shown in ALL calculations. 2. Round off your answers to TWO decimal places where applicable. QUESTION 4 4. Iron ore is reduced to iron in blast furnaces. 4.. Name the gas that is used to reduce iron ore. () 4..2 Write a balanced equation for the reduction process. (2) 4..3 Write down the name of the impurity that forms a molten layer on top of the iron. () 4..4 What is the molten slag commercially used for? () 4..5 Name one negative impact that the refining of iron has on the environment. () 4.2 Phosphorus is an important element to living organisms In what natural form does phosphorus exist? () Why is phosphorus important to living organisms? () When phosphorus compounds end up in rivers and streams, what negative effect do they have? () Name the gaseous air pollutant produced when fluorapatite reacts with acids. () What is the advantage of using phosphoric acid over sulfuric acid in a reaction with fluorapatite? (2) [2] Maskew Miller Longman, Focus on Physical Sciences Grade Test 7: Chemical systems Page 3 of 7

4 QUESTION 5 Gold is the most sought after precious metal. 5. Give two reasons why gold is the most sought after metal. (2) 5.2 What property makes it possible for gold to exist as a free element in nature? () 5.3 Consider the compound NaAu(CN) 2 (aq) Name the process that produces this compound. () Which element is used to reduce this compound to gold? () 5.4 State one negative impact that gold mining has on the environment. () [6] QUESTION 6 Extensive use of coal has created major environmental problems. 6. State two uses of coal in South Africa. (2) 6.2 What environmental problems have been created by excessive coal burning? (2) [4] QUESTION 7 Crude oil is a mixture of chemicals. 7. What physical property of these chemicals is used to separate them? () 7.2 Explain the term catalytic cracking. (2) 7.3 Hydrocarbons are derived from crude oil What are hydrocarbons? () Write down the structural formula for 2-methylbutane. (2) Write down the IUPAC name for the following compound: (2) [8] Maskew Miller Longman, Focus on Physical Sciences Grade Test 7: Chemical systems Page 4 of 7

5 QUESTION 8 8. Which layer of the atmosphere is most vulnerable to CFC pollution? Give a reason for your answer. (2) 8.2 Name two gases that form acid rain. (2) 8.3 State one negative effect of acid rain. () [5] TOTAL SECTION B: 35 GRAND TOTAL: 45 Maskew Miller Longman, Focus on Physical Sciences Grade Test 7: Chemical systems Page 5 of 7

6 DATA FOR PHYSICAL SCIENCES GRADE CHEMISTRY PHYSICAL CONSTANTS NAME SYMBOL VALUE Avogadro s constant N A 6, mol Molar gas constant R 8,3 J K mol Standard pressure p θ, Pa Molar gas volume at STP V m 22,4 dm 3 mol Standard temperature T θ 273 K FORMULAE p V T = p V 2 2 T pv = nrt 2 n = m M c = n V c = MV m n a nb = c V a a c b V b Printed with permission, National Department of Education Maskew Miller Longman, Focus on Physical Sciences Grade Test 7: Chemical systems Page 6 of 7

7 (I) H 3 Li 7 Na 23 9 K Rb Cs Fr 2 (II) 4 Be 9 2 Mg Ca Sr Ba Ra 226 THE PERIODIC TABLE OF ELEMENTS (III) 5 B 4 (IV) 5 (V) 6 (VI) 7 (VII) 8 (VIII) 2 He 4 0 Ne 20 8 Ar Kr Xe 3 86 Rn,0 2,,5 2,0 2,5 3,0 3,5 2,8 3,0 4,0 3 Al 6 C 2 4 Si 7 N 4 5 P 8 O 6 6 S Se 9 F 9 7 Cl 35,5 35 Br I At 0,9,2,5 2, 2,5 2 Sc Ti Ge Sn 3 33 As 75 5 Sb 0,8,0,3, V ,5 Cr Mn Fe Co Ni Cu 63, ,0 2,4 Y Zr Zn Ga Te Po 0,8,0,2,4 2,2 2,2 2,2,7,7 2, 2,5 2,5 La Hf Nb Mo Tc Ru 0 76 Rh Pd Ag Cd 2 80 In Pb Bi 209 0,7 0,9 79 Ta 8 W ,0 KEY Atomic number Ac Re Cu 63,5 Electronegativity Symbol Os 90 Ir 92 Pt 95 Au 97 Hg 20 Tl Ce Pr 4 60 Nd 44 6 Pm 62 Sm Eu Gd Tb Dy Th Pa 92 U Np 94 Pu 95 Am 96 Cm Printed with permission, National Department of Education 97 Bk Ho Es 68 Er Tm 69 0 Md 70 Yb No 7 Lu Lr 0,7 0,9 Approximate relative atomic mass Maskew Miller Longman, Focus on Physical Sciences Grade Test 5: Atomic nuclei Page 7 of 7