Year 10 Science Chemistry Examination November 2011 Part A Multiple Choice

Transcription

1 Year 10 Science Chemistry Examination November 2011 Part A Multiple Choice Answer these questions on the multiple choice answer sheet provided 2 Isotopes have been found as variations of atoms. Which of the following best describes isotopes? A. They have different numbers of protons B. They have different numbers of neutrons C. They have different numbers of electrons D. They have different electron shells 3 An element has an atomic number of 16. Which of the following describes its position in the periodic table? A. Period 2 group 6 B. Period 6 group 2 C. Period 3 group 6 D. Period 6 group 3 4 The modern periodic table is based on the increasing number of:- A. Neutrons B. Protons C. Electrons D. Morons 5 Which of the following best describes an element that is a metal? A. Small number of valence electrons, good conductor, tends to make cations in a reaction. B. Large number of valence electrons, good conductor, tends to make cations in a reaction. C. Small number of valence electrons, good conductor, tends to make anions in a reaction. D. Small number of valence electrons, poor conductor, tends to make cations in a reaction. 1

2 Year 10 Science Chemistry Examination November 2011 Part A Multiple Choice 6 Aluminium metal can react with chlorine to make a compound. Which of these describes what happened to the Aluminium. A. It lost 2 electrons to make a cation with a charge of +2 B. It lost 3 electrons to make a cation with a charge of +3 C. It gained 3 electrons to make a cation with a charge of +3 D. It lost 3 electrons to make a anion with a charge of -3 7 When carbon reacts with oxygen to make a compound:- A. It loses 4 electrons to each oxygen atom to make double ionic bonds B. It shares 2 electrons with each oxygen atom to make covalent bonds C. It shares 4 electrons with each oxygen atom to make double covalent bonds D. It gains 4 electrons from each oxygen atom to make double ionic bonds 8 The correct way to write the formula for Aluminium Sulphate is: A. Al SO 4 B. Al 3 (SO 4 ) 2 C. Al 2 SO 4 3 D. Al 2 (SO 4 ) 3 9 Which of the following shows the correct balanced equation for the reaction between copper nitrate and sodium carbonate? Cu NO 3 (aq) + Na CO 3(aq) Cu CO 3 (s) + 2 Na NO 3 (aq) Cu (NO 3 ) 2 (aq) + Na 2 CO 3(aq) Cu CO 3 (aq) + 2 Na NO 3 (s) Cu (NO 3 ) 2 (aq) + Na 2 CO 3(aq) Cu CO 3 (s) + 2 Na NO 3 (aq) Cu (NO 3 ) 2 (aq) + Na 2 CO 3(aq) Cu CO 3 (aq) + 2 Na NO 3 (aq) 2

3 Year 10 Science Chemistry Examination November 2011 Part A Multiple Choice 10 Which of the reactions shown below is a single displacement reaction? A. AgNO 3 + NaCl AgCl + NaNO 3 B. CuCO 3 CuO + CO 2 C. Mg + CuSO 4 Cu + MgSO 4 D. CH 3 OH + 2O 2 CO 2 + 2H 2 O 11 Which of the equations shown below for the combustion of pentane is correctly balanced? A. C 5 H O 2 5CO H 2 O B. C 5 H 12 + O 2 CO 2 + H 2 O C. C 5 H O 2 5CO 2 + 6H 2 O D. C 5 H O 2 5CO 2 + 6H 2 O 12 Which pair of the ionic solutions shown below will produce a precipitate when they are mixed. A. Sodium sulphate and copper chloride B. Copper nitrate and potassium carbonate C. Zinc nitrate and sodium chloride D. Aluminium Chloride and copper nitrate 13 Fred has been doing an experiment to test the law of conservation of mass. He heated steel wool (iron metal) carefully in a crucible. He weighed the crucible before and after the reaction which is shown by the equation below. 4Fe (s) + 3O 2 (g) 2Fe 2 O 3(s) A. There will be no change in the weight of the crucible B. There will be a decrease in the weight of the crucible C. There will be an increase in the weight of the crucible D. He proved that the law of conservation is incorrect 3

4 Question 1 An unknown element has the symbol 33 15X. a) What is the atomic number for this element? b) What is the mass number for this element? c) How many electrons does the atom for this element have? d) Draw a diagram to show the electron structure for this element. Question 2 Use electron dot diagrams, showing only outer shells, to draw diagrams of the following molecules. a) Water H 2 O b) Carbon Dioxide CO 2 c) Nitrogen N 2 d) Methane CH 4 6

5 Question 3 (2 marks) Draw diagrams, using electron shells, to show how an atom of Sodium can react with an atom of Fluorine to make Sodium Fluoride. Question 4 Write balanced formula for the following ionic compounds. a) Sodium Chloride b) Magnesium Oxide c) Potassium Sulphate d) Ammonium Phosphate 7

6 Question 5 Write balanced equations, using symbols, to show each of the following reactions. a) Decomposition of Copper Carbonate. b) Combustion of Ethanol (CH 3 CH 2 OH) c) Single displacement of Copper metal with Silver Nitrate solution. d) Combination reaction of Magnesium metal with Oxygen gas. Question 6 Use the table of solubility provided to answer questions about which of the reactions below will produce a precipitate. Reaction 1 Copper Sulphate + Ammonium Nitrate Reaction 2 Silver Nitrate + Potassium Chloride Reaction 3 Magnesium Chloride + Sodium Chloride a) Which reaction produces a precipitate? b) Write the correct formula for the precipitate. c) Write a balanced symbol equation for the reaction that produces the precipitate. 8

7 Question 9 The following equations are unbalanced, although the formulas are correct. Balance the equations by putting the correct coefficient in the boxes. C 2 H 4 + O 2 CO 2 + H 2 O CO + O 2 CO 2 Al + Fe 2 O 3 Fe + Al 2 O 3 CO 2 + H 2 O C 6 H 12 O 6 + O 2 Question 10 (6 marks) The periodic table was developed by Mendeleev to help organize the elements. Discuss the periodic table to show your understanding of it by answering the following questions. a) What is special about the Noble Gases and why do they not react with other elements? b) What is meant by period and group? c) How do they relate to electron shells? d) Which part do the periodic table do metals belong in? e) What is special about the electrons for metals? f) Why do all elements in group 7, (the Halogens), have similar properties? g) Carbon has two isotopes. What are isotopes? h) Why are the chemical properties of isotopes similar? 9