ACSBR 3 Chemical Equations - Assignment

Anglo-Chinese School (Barker Road) A Methodist Institution Founded in 1886 CHEMISTRY DEPARTMENT OF SCIENCE Name: ( ) Class: SEC 3 CHEMICAL FORMULAE & EQUATIONS – ASSIGNMENT ALEX LEE/2010 PAGE 1 OF 4 PURE/COMBINED/N-LEVEL Multiple-Choice Questions [20 Marks] TOTAL SCORE / 30 Write in your selected answer for the multiple-choice questions in the boxes provided. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 1. Which of the following ions is not a molecular ion? A ammonium ion B hydroxide ion C nitrate ion D sulfide ion 2. Which of the following substances contains both covalent and ionic bonds? A Al2O3 B C6H12O6 C NH4NO3 D SiO2 3. In which of the following sets do all the compounds contain only ionic bonds? A calcium oxide; carbon dioxide; magnesium oxide B calcium oxide; magnesium oxide; sodium chloride C carbon dioxide; copper(II) sulfate; hydrogen chloride D copper(II) sulfate; hydrogen chloride; magnesium oxide 4. What is the chemical formula for barium hydroxide? A BaOH B Ba(OH)2 C BaOH2 D (Ba)OH3 5. What is the chemical formula for copper(II) nitrate? A CuNO3 B Cu2NO3 C Cu3NO2 D Cu(NO3)2 6. What is the formula for diphosphorus pentaoxide? A PO4 B PO5 C P2O5 D P3O4

ALEX LEE/2010 PAGE 2 OF 4 7. What are the formulae for ammonia, carbon dioxide and methane? ammonia carbon dioxide methane A AH CO2 MH4 B NH3 CO2 CH4 C NH4 C2O2 MH4 D A2H CO2 CH4 8. An unknown element X forms an ionic compound of the formula X2SO4. What is the formula for the ion of X? A X+ B X2+ C X3+ D X4+ 9. An unknown element Y forms a compound Al2Y3 with aluminium. What is the formula of the compound formed between Y and magnesium? A MgY B MgY2 C MgY3 D Mg2Y3 10. What is the chemical formula for diamond and graphite? diamond graphite A C C B C C60 C C4 C D C4 C60 11. A portion of an ionic lattice is shown below. Legend: element Q element R What is the formula of this compound? A QR B Q2R C QR4 D Q13R14 12. What is the number of electrons present in a carbonate ion? A 28 B 30 C 32 D 36 13. Seven gaseous elements are listed below. argon chlorine fluorine helium hydrogen nitrogen oxygen How many of the above elements occur naturally as diatomic molecules? A 4 B 5 C 6 D 7

ALEX LEE/2010 PAGE 3 OF 4 14. Several elements and their formulae are shown below. Which formula is incorrect? A bromine, Br B iodine, I2 C krypton, Kr D nitrogen, N2 15. Several elements and their formulae are shown below. Which formula is incorrect? A argon, Ar B hydrogen, H2 C magnesium, Mg2 D sodium, Na 16. A chemical equation is shown below: a NH3 + b CH4 + c O2 ⎯→ d HCN + e H2O Given that a, b, c, d a n d e a r e t h e s m a l l e s t p o s s i b l e i n t e g e r v a l u e s f o r t h e e q u a t i o n t o b e balanced, what is the value of e? A 2 B 4 C 6 D 7 17. A chemical equation is shown below: a CH3(CH2)3COOH + b O2 ⎯→ c CO2 + d H2O Given that a, b, c and d are the smallest possible integer values for the equation to be balanced, what is the value of b? A 6 B 7 C 13 D 15 18. Some iron fillings were burnt in the presence of oxygen, forming iron(III) oxide. Which of the following equations correctly represents this reaction? A 2 Fe + 3 O ⎯→ Fe2O3 B 3 Fe + O2 ⎯→ Fe3O2 C 4 Fe + 3 O2 ⎯→ 2 Fe2O3 D Fe2 + O3 ⎯→ Fe2O3 19. When solutions of barium chloride and lead(II) nitrate are mixed, a white precipitate of lead(II) chloride is formed, leaving a solution of barium nitrate as the byproduct. Which of the following equations correctly represents this reaction? A BaCl2 (l) + 2 Pb(NO3)2 (l) ⎯→ 2 PbCl2 (s) + Ba(NO3)2 (l) B BaCl2 (aq) + PbNO3 (s) ⎯→ BaNO3 (s) + PbCl2 (s) C Pb(NO3)2 (aq) + 2 BaCl2 (aq) ⎯→ 2 PbCl2 (s) + Ba(NO3)2 (aq) D Pb(NO3)2 (aq) + BaCl2 (aq) ⎯→ Ba(NO3)2 (aq) + PbCl2 (s) 20. Which of the following equations best represents water boiling? A 2 H2O (l) ⎯→ 2 H2 (g) + O2 (g) B H2O (aq) ⎯→ 2 H (g) + O (g) C H2O (aq) ⎯→ H2O (g) D H2O (l) ⎯→ H2O (g)

ALEX LEE/2010 PAGE 4 OF 4 Structured Questions [10 Marks] 21. Construct balanced chemical equations, including state symbols, for the chemical reactions as described below. [10] (a) Aluminium combines directly with chlorine to form aluminium chloride. (b) Zinc metal reacts with dilute nitric acid to form aqueous zinc nitrate and hydrogen. (c) Ammonia reacts oxygen to form nitrogen monoxide and water vapour. (d) Hydrogen is produced when methane is reformed with steam. Carbon monoxide is a byproduct of this industrial process. (e) Iron reacts with dilute silver nitrate, forming aqueous iron(II) nitrate and silver. END