Answer All Questions :

1 Which of the following formula of the compound is true?  

Compound Formula

A Lead(II) sulphate Pb2SO4

B Ammonium nitrate (NH4)2NO3

C Aluminium oxide AlO3

D Barium nitrate Ba(NO3)2

   2

Table 1 shows the results to determine the empirical formula of a substance. What is the empirical formula of the substance?

X Y

Ratio of moles 1 1.5

Table 1A XY C X3 Y

B XY3 D X2Y3

3 Which of the following is not matched correctly?

SubstanceBahan

Formula

SodiumNatrium

Na

Copper(II) sulphateKuprum(II) sulfat

CuSO4

Potassium oxideKalium oksida

K2O

Ammonium nitrateAmmonium nitrat

NH4(NO3)2

4 Diagram 4 shows the set –up of apparatus in an experiment to determine the emperical formula of a metal oxide.Rajah 4 menunjukkan susunan radas bagi menentukan formula empirik bagi satu oksida logam.

Diagram 4Rajah 4

Which of the following metals oxide is suitable to be used in the experiment?Oksida logam yang manakah paling sesuai di gunakan di dalam eksperimen tersebut?

A Magnesium oxideMagnesium oksida

C Calcium oxideKalsium oksida

B Aluminium oxideAluminium oksida

D Copper(II) oxideKuprum(II) oksida

5 The equation shows a reaction between silver nitrate solution and sodium chloride solution .Persamaan di bawah menunjukkan tindak balas antara larutan argentum nitrat dan larutan natrium klorida.

AgNO3 (aq) + NaCl(aq) → NaNO3 (aq) + AgCl(s)

Calculate the mass of silver chloride formed when 0.2 mol of silver nirate solution is added to 0.1 mol of sodium chloride ?[ Relative atomic mass : Cl = 35.5 ,Ag = 108]Hitung jisim argentum klorida yang terbentuk apabila 0.2 mol larutan argentum nitrat ditambahkan kepada 0.1 mol larutan natrium klorida?{ Jisim atom relatif : Cl = 35.5, Ag =108}

A 28.7 g C 21.5 g

B 14.35g D 43.05g

6 Which of the following contains 3 moles of atoms?[S, 32; C, 12 ; Cu , 64 ;O, 16; Avogadro constant= 6.0 X 1023.]

I 96 g of sulphurII 36 g of carbonIII 18 x 1023 atoms of copperIV 132 g of carbon dioxide

A I and II only C II and III onlyB I and IV only D I ,II and III only

7 How many grams of carbon dioxide would contain the same number of atoms as in 2 moles of sulphur dioxide, SO2 ?[ S , 32 ; O , 16; C, 12]

A 11 C 44B 22 D 88

8 The equation below shows the decomposition of copper(II) nitrate on heating.

2Cu( NO3)2 → 2 CuO + 4NO2 + O2

What is the total volume of gas produced at room temperature when 9.4 g of copper(II) nitrate is decomposed completely?[ Relative atomic mass : Cu ,64; N, 14; O,16; 1 mole of gas occupies 24 dm3 at room temperature]

A 0.6 dm3 B 1.2 dm3 C 2.4 dm3 D 3.0 dm3

9 Calculate the mass of carbon dioxide that will be produced at room temperature when 10 g of calcium carbonate is reacted with excess hydrochloric acid according to the equation below. :

CaCO3 (s) + 2HCl(aq) → CaCl2 (aq) + H2O( l )+ CO2(g)

[ Relative atomic mass :Ca, 40; O, !6:C, 12]

A 0.44 g B 2.2 g C 4.4 g D 44 g

10 Which of the following is the correct element and symbol ?

Element Symbol

A Nitrogen NiB Potassium PC Copper CD Magnesium Mg

11 The empirical formula of the carbonate of metal X is X2 CO3 . Its relative molecular mass is 16. What is the relative atomic mass of X ?[Relative atomic mass: C, 12; O , 16 ]

A. 11 B. 22 C. 23 D. 44

12

An element W forms a chloride with the formula of WCl3.What is the formula of sulphate , SO4

-2 formed by W ?

A WSO4 B W2SO4

C W2 (SO4)3 D W3 (SO4 )2

12 Calculate the volume occupied by 16.0 g of oxygen gas at stp [ Ar of O = 16, 1 mol gas occupies a volume of 22.4 dm3 at stp ]

A 1.4 dm3 B 2.8 dm3 C 5.6 dm3 D 11.2 dm3

13 Calculate the number of molecules present in 0.56 dm3 of carbon dioxide gas at stp. [ 1 mole of gas occupies a volume of 22.4 dm3 at stp, NA = 6.0 X 1023 mol-1 ] A 1.2 X 1022 B 1.5 X 1022 C 1.2 X 1023 D 1.5 X 1023

14 What is the mass of carbon dioxide, CO2 gas that contains the same number of molecules as 2.2 g of propane gas, C3H8 ? [ Use the information that the relative atomic mass of H = 1, C = 12, O = 16 ] A 2.2 g B 3.3 g C 4.4 g D 5.5 g

Answer all the question in this section:Part A : Structure questions

1. Figure 1 shows the set-up of apparatus for an experiment to determine the empirical formula of magnesium oxide

Figure 1Results :Mass of crucible + lid = 24.0 gMass of crucible + lid + magnesium ribbon = 26.4 gMass of crucible + lid + magnesium oxide = 28.0 g

(a) What is meant by empirical formula ?.

………………………………………………………………………………………[ 1 marks ]

(b) What is meat by molecular formula ?

………………………………………………………………………………………[ 1 marks ]

(c) Based on the above results,(i) determine the empirical formula of magnesium oxide [4 marks]

[ Relative atomic mass : O , 16 ; Mg, 24 ]

(i) write the chemical equation for the reaction in the experiment

………………………………………………………………………………[ 1 mark ]

(d) Why was the crucible lid opened once in a while during the experiment?.

………………………………………………………………………………………[ 1 mark ]

e) Why was the magnesium ribbon cleaned with sand paper before heating ?.

………………………………………………………………………………………[ 1 marks ]

f) Why was the crucible covered with the lid as soon as the magnesium started burning ?

……………………………………………………………………………………..[1 marks ]

g) How does to make sure that the reaction is complete ?

……………………………………………………………………………………[ 1 marks ]

(e) Metal X is placed below hydrogen in the reactivity series. How does the above experiment suitable for determining the empirical formula of metal X ?. Explain the reason and suggest the experiment .

……………………………………………………………………………………[ 3 marks ]

2. A student carried out an experiment to determine the empirical formula of aluminium oxide. The steps and set-up of apparatus of the experiment are shown in the figure below.

Step Set-up of apparatus1. Crucible and lid are weighed.

2. Crucible, lid and aluminium strip are weighed.

3. Aluminium strip is heated until the reaction is complete.

4. Crucible, lid and aluminium oxide are weighed when cooled.

(a) Complete the following table by stating the observations and related inferences in the experiment.

Observations Inferences(i)

(ii)

(i)

(ii)

[6 marks]

(b) The mass of crucible and lid: gThe mass of crucible, lid and aluminium strip: gThe mass of crucible, lid and aluminium oxide when cooled: g

[3 marks](c) (i) What is the mass of aluminium that has been used?

(ii) What is the mass of oxygen which reacted with aluminium?

(iii) Determine the empirical formula of aluminium oxide.Use the information that relative atomic mass, Al = 27 and O = 16.

[3 marks]

(d) Based on your answer in (c)(iii), how many moles of aluminium and oxygen atoms have reacted?

[3 marks]

3.(a) Find the relative molecular mass and chemical formula. Then, complete the table

below.

Substance Chemical formula Relative molecular mass

  Sodium carbonate    

  Copper sulphate    

  Potassium carbonate    

  Aluminium nitrate    

Aluminium Sulphate

Zinc Nitrate

[Relative atomic mass: C = 12; N = 14; O = 16; Na = 23; Al = 27; S = 32; K = 39; Cu = 64 ; Zn = 35.5 ]

[6 marks]

(b) How many molecules are found in:(i) 16.2 g of carbon dioxide?

(ii) 22.5 dm³ carbon dioxide at s.t.p.?[Avogadro constant = 6.02 × 10²³; 1 mol of gas occupies 22.4 dm³ at s.t.p.]

[2 marks]

(c) Calculate the mass of (i) sodium carbonate that contains the same number of molecules in 21.3 g of

carbon dioxide.

[2 marks](ii) copper sulphate that contains the same number of molecules in 12.5 g of

hydrogen.

[2 marks]

4.a) Calculate the number of molecules present in 0.56 dm3 of carbon dioxide gas at stp. [ 1 mole of gas occupies a volume of 22.4 dm3 at stp, NA = 6.0 X 1023 mol-1 ] [ 3 marks ]

b) Calculate the volume occupied by 16.0 g of oxygen gas at stp [ Ar of O = 16, 1 mol gas occupies a volume of 22.4 dm3 at stp ]

[ 3 marks ]

c)The empirical formula of the carbonate of metal X is X2 CO3 . Its relative molecular mass is 16. What is the relative atomic mass of X ?[Relative atomic mass: C, 12; O , 16 ]

[ 3 marks ]

d)The equation below shows the decomposition of copper(II) nitrate on heating.

2Cu( NO3)2 → 2 CuO + 4NO2 + O2

What is the total volume of gas produced at room temperature when 9.4 g of copper(II) nitrate is decomposed completely?

[ Relative atomic mass : Cu ,64; N, 14; O,16; 1 mole of gas occupies 24 dm3 at room temperature]

[ 4 marks]

e)Calculate the mass of carbon dioxide that will be produced at room temperature when 10 g of calcium carbonate is reacted with excess hydrochloric acid according to the equation below. :

CaCO3 (s) + 2HCl(aq) → CaCl2 (aq) + H2O( l )+ CO2(g)

[ Relative atomic mass :Ca, 40; O, !6:C, 12][ 4 marks ]

Part B : Essay Question

1. (b) The figure below shows the standard representation for an atom of element Na

State three types of information that can be deduced ? Draw the electron arrangement for an atom of element Na

[5 marks](c) The information below is regarding substance X

(i) Determine the empirical formula of substance X.[Given that the relative atomic mass of C = 12 , H = 1]

Carbon 85.70%

Hydrogen 14.30%

Relative molecular mass = 56

(ii) Determine the molecular formula of substance X.

(iii) Based on the answers in (a)(i) and (a)(ii) , compare and contrast the empirical formula and the molecular formula.

[ 8 marks]

SMK SIMPANG BEKOHASAHAN , MELAKA

APRIL TEST 2009

CHEMISTRY

FORM 4

TIME : 1 HOUR

NAME : ………………………………………..

FORM : ……………………………..

SULIT4541/2APRIL TEST1 HOUR

Prepared By :

(……………………….)Pn.Rozilah YunusChemistry teacher

Verified By :

(……………………)Pn.Normah Abd KadirGKMP Science and Mathematic