Unit 3 Chemistry. Practice Exam Question and Answer Booklet. A non-profit organisation supporting students to achieve their best.

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marks be answered A 20 20 20 B 8 8 50 Total 70 Students are permitted to bring into the examination room: pens, pencils, highlighters, erasers, rulers and a scientific calculator.

1 A non-profit organisation supporting students to achieve their best. Practice Exam Question and Answer Booklet Duration: 15 minutes reading time, 90 minutes writing time Structure of book: Section Number of questions Number of questions to Number of marks be answered A B Total 70 Students are permitted to bring into the examination room: pens, pencils, highlighters, erasers, rulers and a scientific calculator. Students are not permitted to bring into the examination room: blank sheets of paper and/or white out liquid/tape. Materials supplied: This question and answer booklet of 14 pages. Instructions: You must complete all questions of the examination. Write all your answers in the spaces provided in this booklet.

2 Engage Education Foundation Section A Multiple-choice questions Instructions Answer all questions by circling your choice. Choose the response that is correct or that best answers the question. A correct answer scores 1, an incorrect answer scores 0. Marks will not be deducted for incorrect answers. No marks will be given if more than one answer is completed for any question. Questions Questions 1 and 2 refer to the following information: 0.12 g of a metal was reacted with excess hydrochloric acid. 125 ml of hydrogen gas was collected at 27 C and 100 kpa. Question 1 The amount of hydrogen gas, in mol, would be closest to: A. 5.0 B C D Question 2 The metal involved could be: A. zinc B. sodium C. calcium D. magnesium Question 3 The nitrogen atoms from the excess amino acids in our body are removed from the human body as A. N 2 B. NH 3 C. NH 4NO 3 D. CO(NH 3) 2 Question 4 The amino acid, alanine, dissolves in water. In an aqueous solution with a ph = 7, alanine is acting as: A. an acid only. B. a base only. C. neither an acid nor a base. D. both an acid and a base. Page hour revision VCEseminars for just $52 visit for more info.

3 Engage Education Foundation Question 5 Cellulose cannot be digested by humans because: A. it is insoluble in water. B. it contains no glucose. C. it is not a carbohydrate. D. the enzymes required to catalyse its hydrolysis are not present in humans. Question 6 How many hydrogen atoms are there in a molecule of 3-nonanol? A. 9 B. 19 C. 20 D. 21 Question 7 The number of structural isomers with the formula C 4H 9Cl is: A. 1 B. 2 C. 3 D. 4 Question 8 A chemist discovers that the journal he subscribes to has a strange smell. He decides to identify the substance, or substances, responsible for this smell. Which of the following analytical methods would be the most likely choice for the first stage of an analysis? A. gas-liquid chromatography B. paper chromatography C. lame tests D. atomic absorption spectroscopy Question 9 If three glycine molecules (relative molecular mass 75) react together to form a tripeptide, the relative molecular mass of the product would be: A. 171 B. 189 C. 207 D. 225 Question 10 This reaction between two or more amino acids to form a polypeptide is classified as: A. condensation. B. esterification. C. hydrolysis. D. nitrification. Page 2

4 Engage Education Foundation Question 11 A substance that could be formed as a product, when a polysaccharide undergoes enzyme catalysed hydrolysis, is: A. H 2O B. CO 2 C. C 6H 12O 6 D. CH 2OH.CHOH.CH 2OH Question 12 Consider the reaction: CH 3CH = CHCH 3 + Br 2 Z Z would likely represent: A. CH 3CHBrCHBrCH 3 B. CH 2BrCH 2CHBrCH 3 C. CH 3CHBrCH 2CH 2Br D. CH 2BrCH 2CH 2CH 2Br Question 13 A sample of hydrocarbon contains 81.8% carbon by mass. The empirical formula of the compound would be: A. CH 4 B. CH 3 C. C 2H 5 D. C 3H 8 Question 14 Concentrated sulfuric acid reacts with glucose. One of the chemical reactions that can occur may be represented as: C 6H 12O 6(s) + 6H 2SO 4(l) 6C(s) + 6H 3O + (aq) + 6HSO 4 (aq) This reaction is best described as being: A. dehydration only. B. acid-base and redox only. C. dehydration and acid-base only. D. dehydration, acid-base and redox. Question 15 An aqueous mixture of two substances (Y and Z) is subjected to analysis by both paper chromatography and high performance liquid chromatography (HPLC). In both forms of chromatography, component Z of the mixture was bonded more strongly to the stationary phase than component Y. In terms of Rf and Rt, where Rt is the retention time in HPLC, component Z has the: A. Higher Rf Lower Rt B. Higher Rf Higher Rt C. Lower Rf Lower Rt D. Lower Rf Higher Rt Page hour revision VCEseminars for just $52 visit for more info.

5 Engage Education Foundation Question 16 A 2.0 L sample of a gaseous hydrocarbon is burnt in excess oxygen. The only products of the reaction are 8.0 L of CO 2(g) and 10.0 L of H 2O(g), all at 100ºC and 1 atm pressure. The formula of the hydrocarbon is: A. CH B. C 2H 4 C. C 4H 10 D. C 8H 10 Question 17 Which of the following could not be a product of the reduction of sulfuric acid when it acts as an oxidant? A. S B. H 2S C. SO 2 D. H 2S 2O 7 Question 18 Which of the following compounds of manganese can be reduced to form the other three? A. MnO B. MnO 2 C. KMnO 4 D. K 2MnO 4 Question 19 What mass of barium nitrate is required to produce 5.0g of barium sulphate in the presence of excess sodium sulphate? A. 5.0g B. 5.6g C. 6.0g D. 6.6g Question 20 How many double bonds exist in the straight-chain carboxylic acid, C 12H 18O 2? A. 1 B. 2 C. 3 D. 4 Page 4

6 Engage Education Foundation Section B Short-answer questions Instructions Answer all questions in the spaces provided. In questions where more than one mark is available, appropriate working must be shown. Unless otherwise indicated, the diagrams in this book are not drawn to scale. Questions Question 1 a. Enzymes are an important part of our body. They perform many functions. Complete the table below by describing the components that make up the primary, secondary and tertiary structure. Primary Brief Description Secondary Tertiary b. A student carries out the following experiments on different enzymes: In experiment A, they were heated from 25 C to 100 C. In experiment B, they were added to hot concentrated acid. Choose one experiment and explain how it affects the structure of the enzyme. 3 marks Total: 5 marks Page hour revision VCEseminars for just $52 visit for more info.

7 Engage Education Foundation Question 2 a. Maltose is a disaccharide formed from the reaction of two glucose molecules. Draw a molecule of maltose and label the ether linkage. b. When maltose is formed there is another product. Give the chemical formula for this product. c. A polysaccharide is made from 9 glucose molecules. Calculate the mass of the polysaccharide if you have 0.12 mol of it. 3 marks Total: 6 marks Page 6

8 Engage Education Foundation Question 3 a. Explain the principles of fractional distillation. b. Draw and name one possible structure for the alkanols with: i. 4 carbon atoms ii. 6 hydrogen atoms = c. A student wishes to separate the above alkanols using fractional distillation. Which alkanol should they expect to collect first? Explain. Total: 6 marks Page hour revision VCEseminars for just $52 visit for more info.

9 Engage Education Foundation Question 4 a. Fatty acids are a form of lipid. They have a carboxyl group attached to a long hydrocarbon chain. Using the polarity of fatty acids explain if a long fatty acid chain is likely to be soluble in water. b. Triglycerides are formed as a result of a condensation reaction between an alcohol and 3 fatty acid molecules. Name and draw this alcohol. Total: 4 marks Page 8

10 Engage Education Foundation Question 5 a. Fill in the blanks: In a high ph environment amino acids act as. They do so by a hydrogen ion and developing an overall charge. b. Generally, amino acids exist in a cationic, anionic or a dipolar form. What is the name given to an amino acid when it is in its dipolar form? c. Glycine and alanine can react together to form two different compounds dipeptides. Draw these two dipeptides. Total: 5 marks Page hour revision VCEseminars for just $52 visit for more info.

11 Engage Education Foundation Question 6 a. While cleaning his house a chemist sees that an active ingredient in the cleaning liquid he is using is molecule X. He concludes that molecule X is an ester present in the detergent to give its signature orange smell. Draw a reaction pathway for the production of molecule X with starting molecules octane and ethene, given that an intermediary step involves the production of ethanoic acid. b. Name molecule X. 3 marks Total: 4 marks Page 10

12 Engage Education Foundation Question 7 a. A student wants to calculate the amount of common table salt in a piece of biscuit. In order to do so he decides to first remove all the water. He finds that the biscuit was 37% water. If the initial mass of the biscuit was 5.6g what is the final mass (after analysis)? b. The student then completely dissolves the biscuit in water. Which metal element should he isolate (separate out into a compound) in order to find the amount of salt? c. The student adds excess potassium nitrate to the solution in order to isolate the mental element from the rest of the biscuit. Is the student going to be successful in calculating the amount of salt in the biscuit? Explain with the aid of a chemical equation. d. Another student decides to carry out the same experiment, except instead of isolating a metal element to find the amount of salt, he decides to isolate a non-metal element. Name this element. e. After preparing a solution of the dried biscuit, the student adds excess lead (II) nitrate. Write an equation of the reaction that takes place. Page hour revision VCEseminars for just $52 visit for more info.

13 Engage Education Foundation f. The student collects the precipitate and after weighing to constant mass he finds that the precipitate weighs 1.3g. What percentage of the biscuit is salt? 4 marks g. The percentage of salt calculated is much higher than the percentage stated on the biscuit packet. Identify and explain one possible error that would account for this. Total: 1 Page 12

14 Engage Education Foundation Question 8 The fictional city of Milburn has a high rate of underground criminal activity. This activity culminated came to an end when the Milburn Police Force discovered Fat Tony at the bottom of Port MacKillop Bay, weighed down by concrete boots (that is, Fat Tony s feet were enclosed in a block of cement). It is wellknown that there are two large concrete-producing factories with mob-connections in Milburn, and so the police contract a team of forensic chemists to compare the sample found with Fat Tony to samples from each of the concrete factories. The forensic chemists decided to use Atomic Absorption Spectroscopy (AAS) to quantitatively test for the presence of iron. The results from their experiment are as follows: Iron concentration (mg/l) Abs 1 Abs 2 Abs 3 Mean Absorbance From these results, the chemists were able to plot a calibration curve, with absorbance on the Y axis and concentration on the X axis. The equation for the line of best fit was also calculated. Absorbance y = x R² = Concentration (mg/l) For each sample, between 0.35g and 0.45g of the concrete was crushed and dissolved in 100mL volumetric flasks. Triplicate measurements were taken for each sample: Sample Mass of sample (g) Absorbance Fat Tony s concrete A Fat Tony s concrete B Fat Tony s concrete C Concrete Factory 1 A Concrete Factory 1 B Concrete Factory 1 C Concrete Factory 2 A Concrete Factory 2 B Concrete Factory 2 C Page hour revision VCEseminars for just $52 visit for more info.

15 Engage Education Foundation a. Fill in the following table: Sample Mean mass of sample (g) Mean Absorbance Iron Concentration (mg/l) Fat Tony s concrete Concrete Factory 1 Concrete Factory 2 b. Identify which concrete factory was most likely involved with the death of Fat Tony. c. Calculate the percentage by mass, %(m,m), of iron in the sample of concrete taken from Concrete Factory 1. d. When the cement samples were run through AAS, a bright orange colour was emitted by the flame once the samples were exposed to the light from the iron cathode lamp used. Explain the origin of this bright orange colour, and why an iron cathode lamp was used as the light source. 3 marks Total: 8 marks End of Booklet Page 14

A level Chemistry Preparation Work

A level Chemistry Preparation Work This booklet is designed to help you prepare for you re A level studies in chemistry. Tasks have been selected to improve your grounding in key skills and concepts that