Answers to all Test yourself Questions (HODDER, EDEXCEL AS CHEMISTRY)

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Answers to Topic 1 Test yourself questions

 1  a) The more reactive metal displaces the less reactive metal from its compound, e.g.
Zn(s) + CuSO₄(aq) → ZnSO₄(aq) + Cu(s)

      b) a metal or hydrogen

      c) Carbon dioxide is produced.

           acid + carbonate → metal compound (salt)+ carbon dioxide + water

      d) They are all white crystalline solids.

 2  a) copper, steel

      b) salt, limestone

      c) ice, sugar

 3  a) C₂H₆O₂

      b) CH₃O

 4  a)

b)           

     

5  a) hydrogen and sulfur, H₂S

      b) chlorine and oxygen, Cl₂O

      c) hydrogen and nitrogen H₃N or NH₃

 6  Because Al(OH)₃ contains one Al atom combined with 3 O atoms and 3 H atoms, whereas AlOH₃ would contain one Al atom combined with only one O atom and 3 H atoms.

 7  a)   (K⁺)₂SO₄²⁻ or K₂SO₄
b)  (Al³⁺)²(O²⁻)₃ or Al₂O₃,
c)   Pb²⁺CO₃²⁻ or PbCO₃
d)  Zn²⁺(OH⁻)₂ or Zn(OH)₂
e)   (Fe³⁺)₂(SO₄²⁻)₃ or Fe₂(SO₄)₃

 8  Molecules: a) octane, c) pure sulfuric acid,
e) phosphorus trichloride

      Ions: b) copper(i) oxide, d) lithium fluoride

9	Non-metal (molecular) compounds	Metal/non-metal (ionic) compounds
a)	low melting temperatures and boiling temperatures	high melting temperatures and boiling temperatures
b)	do not conduct electricity as liquids	conduct electricity as liquids

10  a) CH₄ + 2O₂ → CO₂ + 2H₂O

b)

(10b)

 

11  a) 4Na + O₂ → 2Na₂O

      b) Na₂O + H₂O → 2NaOH

      c) H₂ + Cl₂ → 2HCl

      d) Zn + 2HCl → ZnCl₂ + H₂

      e) CH₄ + 2O₂ → CO₂ + 2H₂O

      f)  2Fe + 3Cl₂ → 2FeCl₃

12  a) hydrogen ions, H⁺(aq) and nitrate ions NO₃⁻(aq)

      b) hydrogen ions, H⁺(aq) and sulfate ions, SO₄²⁻(aq)

13  a) Zn + H₂SO₄ → ZnSO₄ + H₂

      b) CaO + 2HNO₃ → Ca(NO₃)₂ + H₂O

      c) Na₂CO₃ + 2HCl → 2NaCl + CO₂ + H₂O

14  a) Zn + 2H⁺ + SO₄²⁻ → Zn²⁺ + SO₄²⁻ + H₂

           Zn + 2H⁺ → Zn²⁺ + H₂

      b) Ca²⁺O²⁻ + 2H⁺ + 2NO₃⁻ 

→ Ca²⁺ + 2NO₃⁻ + H₂O

           O²⁻ + 2H⁺  → H₂O

      c) 2Na⁺ + CO₃²⁻ + 2H⁺ + 2Cl⁻ 

→ 2Na⁺ + 2Cl⁻ + CO₂ + H₂O

           CO₃²⁻ + 2H⁺ → CO₂ + H₂O

15  a) 12

      b) 2

      c) 8

      d) 3

      e) 4

16  a) 71

      b) 256.8

      c) 46

      d) 154

17  a) 95.3

      b) 159.6

      c) 249.6

18  a) 0.5 mol

      b) 0.05 mol

      c) 1 mol

      d) 0.1 mol

      e) 0.25 mol

19  a) 12.69 g

      b) 17.75 g

      c) 36.0 g

      d) 0.535 g

      e) 12.0 g

20  a) 2 mol

      b) 1 mol

      c) 4 mol

21  a) 3 ´ 10²³

      b) 24 ´ 10²³  = 2.4 ´ 10²⁴

      c) 54 ´ 10²³ = 5.4 ´ 10²⁴

22  a) 0.112 ´ 10⁻³ g Fe³⁺ and 12.4 ´ 10⁻³ g NO₃⁻

      b) 0.002 ´ 10⁻³ mol Fe³⁺ = 2 ´ 10⁻⁶ mol Fe³⁺ and 0.2 ´ 10⁻³ mol NO₃⁻ 

           = 2 ´ 10⁻⁴ mol NO₃⁻

      c) 12 ´ 10¹⁷  = 1.2 ´ 10¹⁸ Fe³⁺ ions and 1.2 ´ 10²⁰ NO₃⁻ ions

23  a) CH₄

      b) VCl₄

      c) Na₂SO₄

24  a) CuFeS₂

      b) H₂SO₄

      c) C₂H₆O

25  14.0 g

26  2.02 g

27  0.33 kg

28  a) 10 mol

      b) = 2 ´ 10⁻³ mol

      c) = 0.125 mol

29  a) 48 000 cm³

      b) 4.8 cm³

      c) 3000 cm³

30  a) 1 dm³

      b) 175 cm³ O₂ forming 100 cm³ CO₂

31  a) C₃H₈(g) + 5O₂(g) → 3CO₂(g) + 4H₂O(g)

      b) 1000 cm³ O₂ forming 600 cm³ CO₂

      c) ´ 12 g mol⁻¹ = 0.3 g CO₂

32  a) 0.01 mol Zn gives 240 cm³ H₂

      b) 0.02 mol KNO₃ gives 0.01 mol O₂ = 240 cm³ O₂

33  a) 0.05 mol dm⁻³

      b) 0.4 mol dm⁻³

      c) 0.625 mol dm⁻³

34  a) ´ 2 = 0.1 mol H₂SO₄ Þ 9.81 g H₂SO₄

      b) ´ 0.01

           = 10⁻³ mol KMnO₄ Þ 0.158 g KMnO₄

      c) ´ 0.2

           = 0.05 mol Na₂CO₃ Þ 5.3 g Na₂CO₃

35  1000 cm³ of mineral water contains 0.133 g of hydrogencarbonate.

      1000 g of mineral water contains 0.133 g of hydrogencarbonate

      Concentration in ppm =´ 10⁶ = 133

36  1 mol Fe₂O₃ → 2 mol Fe

      159.6 g Fe₂O₃ → 111.6 g Fe

      1000 kg Fe₂O₃ →´ 1000 kg Fe = 699 kg Fe

      Theoretical yield = 699 kg

      % yield == 90%

37  1 mol CaO → 1 mol Ca(OH)₂

      56.1 g CaO → 74.1 g Ca(OH)₂

      500 kg CaO →´ 500 kg Ca(OH)₂ 

      = 660 kg Ca(OH)₂

      Theoretical yield = 660 kg

      % yield =´ 100 = 93.9%

38  a) Atom economy

           =´ 100

           =´ 100 = 100%

      b) Atom economy =´ 100 = 51.1%

      c) Atom economy =´ 100 = 68%