Chemistry Handout Smk Bb

YASMIN NA BONUS EXITUS CHYMICIS 2014

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BONUS EXITUS CHYMICIS

NAME : _____________________________________________________

CLASS : _____________________________________________________

NO TOPICS PAGE REMARKS 1 Structure of atoms 2 2 Chemical formulae and equations 7 3 Periodic Table of Elements 11 4 Chemical Bonds 13 5 Electrochemistry 15 6 Acids and Bases 18 7 Salts 21 8 Manufactured substances in the Industry 24


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STRUCTURE OF ATOMS

1. The table below shows four substances and their respective formulae.

Substance Chemical formula

Zinc sulphate ZnSO4

Zinc Zn

Oxygen O2

Naphthalene C10H8

(a) (i) State one substance, which exists as molecules.

[1 mark] (ii) Which substance has the highest melting temperature?

[1 mark] (iii) What is the physical state of zinc sulphate at room temperature?

[1 mark] (iv) Which substance can conduct electricity in the solid state?

[1 mark] (v) Write the formula of the ion formed for the substance in (a)(iv).

[1 mark] (vi) Draw the arrangement of particles in zinc.

[1 mark]


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2. (a) The table below shows the melting points and boiling points of four substances, E, F, G and H.

Substance Melting point (C) Boiling point (C) Physical state

E -130 92

F -130 -71

G 14 114

H 194 232

(i) Fill in the column of physical state in the table above (at room temperature).

[4 marks]

(ii) What type of bond is present in substance F?

[1 mark]

(iii) Which of these substances is a metal?

[1 mark]

(b) The three diagrams below labeled as X, Y and Z. Show the different physical states of a substance.

(i) Is the substance an element or a compound? Give a reason for your answer.

[2 marks]


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3. The diagram below shows the set-up of apparatus used to investigate the change of states of matter for liquid Y.

A colourless liquid Y is heated in an oil bath and changes to a colourless gas at 113C.

(a) Name the process for the change of state of matter from liquid Y to colourless gas at the temperature of 113C.

[1 mark]

(b) Draw the change in the arrangement of particles from liquid Y to colourless gas in the boxes provided.

[2 marks]

(c) Sketch the graph of temperature against time for the heating of liquid Y on the axes provided below.

[2 marks]


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(d) Predict what will be observed on the under surface of the glass slide.

[1 mark]

(e) In this experiment, can water be used to replace the oil in the beaker? Explain.

[2 marks]

(f) The melting point of liquid Y is 18C. Suggest how you would freeze it in the laboratory.

[1 mark]

4.

The table below shows five atoms of elements labeled C, F, H, I and K.

Atom Proton number Number of electrons Nucleon number

C 11 11 23

F 17 17 35

H 17 17 37

I 19 19 39

K 36 36 84

Answer the following questions based on the information given in the table by using the letters as symbols of the elements.

(a) (i) Among the atoms C, F, H, I and K, which are isotopes?

[1 mark]

(ii) Give a reason for your answer given in (a)(i).

[1 mark]

(iii) Do the isotopes show the same chemical properties? Explain your answer.


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[3 marks]

(b) What is the number of valence electrons for element I?

[1 mark]

(c) Element K and I is both in the same period in the Periodic Table.

(i) Which period are they in?

[1 mark]

(ii) Give your reason.

[1 mark]

(d) Atom K is very unreactive towards any chemical. Why?

[1 mark]


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CHEMICAL FORMULAE AND EQUATIONS

1.

The figure below shows the set-up of apparatus of an experiment to determine the empirical formula of copper oxide.

Hydrogen gas is passed through the combustion tube, which contains hot copper oxide.

(a) How is hydrogen gas produced in the laboratory for this experiment?

[1 mark]

(b) Before copper oxide is heated, hydrogen gas is allowed to pass through the apparatus until all the air in the combustion tube is completely removed.

(i) Why should all the air be removed before heating is allowed?

[1 mark]


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(ii) How are you going to ensure that all the air had been removed?

[3 marks]

(c) What is the function of anhydrous calcium chloride in the U-tube?

[1 mark]

(d) Based on the results of the experiment, it is found that 64.00 g of black copper oxide powder left behind a residue of 51.20 g of brownish copper. Determine the empirical formula of copper oxide. [Molar mass: O = 16; Cu = 64]

[2 marks] (e) From the answer given in (d), write a chemical equation for the reaction between

hydrogen and copper oxide.

[1 mark]

(f) The flow of hydrogen gas is continued even though the reaction is complete while the product is allowed to cool to room temperature.

(i) Give one reason why this action needs to be taken.

[1 mark] (ii) Write the chemical equation for the reaction that would take place if the

action in (f)(i). is not taken.

[1 mark]


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2.

The figure below shows the structure formula of glucose.

[Molar mass: H = 1; C = 12; O = 16]

(a) Calculate the relative molecular mass of glucose.

[2 marks]

(b) What is the molecular formula and empirical formula of glucose?

[2 marks]

(c) What is difference between the molecular formula and empirical formula of glucose?

[2 marks] (d) What is the mass of glucose needed to prepare 200 cm and 0.55 mol dm-3 of

glucose solution?

[2 marks]


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(e) Compound Z has the same empirical formula as glucose. The relative molecular mass of Z is 90. What is the molecular formula of Z?

[2 marks]

3.

When 0.35 mole of a hydrocarbon, H, is completely burnt in air, 33.6 dm of carbon dioxide is formed at room temperature and pressure.

(a) Calculate the number of molecules in 0.35 mole of hydrocarbon H. [Avogadro constant = 6.02 10 mol-1]

[1 mark] (b) Calculate the number of moles of 33.6 dm of carbon dioxide.

[1 mol of gas occupies a volume of 24 dm3 at room temperature and pressure]

[1 mark]

(c) Calculate the volume of carbon dioxide formed at r.t.p. From one mole of hydrocarbon H.

[1 mark]

(d) Determine the number of carbon atoms in one molecule of hydrocarbon H.

[2 marks]


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(e) Given that hydrocarbon H rapidly decolourised the reddish brown colour of bromine, what is the homologous series of hydrocarbon H.

[1 mark]

(f) Deduce the molecular formula of hydrocarbon H.

[1 mark] (g) Write down the equation for the complete combustion of hydrocarbon, H.

[2 marks]

PERIODIC TABLE

1.

The table below shows some information about noble gases.

Name Symbol Proton number Boiling point/ C

Helium He 2 -269

Neon Ne 10 -246

Argon Ar 18 -186

Krypton Kr 36 -152

(a) Write the electron arrangement of argon.

[1 mark] (b) Explain why the noble gases are inert.

[2 marks]


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(d) Give two uses of helium.

[2 marks]

2.

The figure below shows some elements in the Periodic Table which are represented by Q, R, S, T, W, X and Y.

T

W R S

Y Q X

Answer the questions below.

(a) Which element has the smallest size?

[1 mark] (b) Which element is most inactive?

Explain your answer.

[2 marks] (c) (i) Which of the elements is a metalloid?

[1 mark] (ii) Write the electron arrangement for the element in (c) (i).

[1 mark]


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(d) (i) Which element is a transition metal?

[1 mark] (ii) State two physical properties of this element.

[2 marks]

(e) Write the chemical equation for the reaction of W with water.

[1 mark] (f) Which element is the most electropositive element?

[1 mark]

CHEMICAL BONDS

1. Table below shows the electron arrangement of elements R, S, and T.

Element Electron arrangement R 2.7 S 2.2 T 2.4

TABLE

a) Based on the elements listed above, state two type of compounds that can be formed.

[2 marks]


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b) Based on your answers in (a), describe the formation of both compounds

[ 14 marks]


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c) State 2 difference between the 2 compounds

[4 marks]

ELECTROCHEMISTRY

1. Diagram below shows the set-up of an electrolytic cell. Beaker I contains a components of a simple chemical cell whereas electrolysis takes place in Beaker II.

(a) State the changes in energy in Beaker I and Beaker II. Beaker I ________________________________________________________________________________________ Beaker II ________________________________________________________________________________________

[2 marks/2 markah]

(b) Which metal is the negative terminal in Beaker I? ________________________________________________________________________________________

[1 mark/1 markah]


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(c)

(i) State the process occurred in the copper electrode in Beaker I.

_____________________________________________________________________________________

[1 mark/1 markah]

(ii) What would you observe at the silver electrode in Beaker I?

_____________________________________________________________________________________

[1 mark/1 markah]

(d) Write equations for reactions, which occurred at anode and cathode in Beaker II. Anode: ________________________________________________________________________________________

[1 mark/1 markah]

Cathode: ________________________________________________________________________________________

[1 mark/1 markah]

(e) (i) What happens to the voltmeter reading when the magnesium electrode in Beaker I is replace with zinc electrode?

_____________________________________________________________________________________

[1 mark/1 markah]

(ii) Explain your reasons in (e) (i).

_____________________________________________________________________________________

[2 marks/2 markah]


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2.. Diagram below shows the arrangement of apparatus for performing electrolysis of a concentrated solution of a salt of sodium.

Diagram

(a) (i) Name the yellowish-green gas released at the anode. __________________________________________________________________________________

[1 mark]

(ii) Give a confirmatory test for the gas which you have stated in (a) i. __________________________________________________________________________________

[1 mark]

(b) (i) Name the colourless gas, which is released at the cathode. __________________________________________________________________________________

[1 mark]

(ii) Write a half equation for the reaction, which occurs at the cathode. __________________________________________________________________________________

[1 mark]

(c) (i) Name the solution of the sodium salt, which is used. __________________________________________________________________________________

[1 mark]


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(ii) Write the formulae of the ions which are present in the solution named in (c) i. __________________________________________________________________________________

[1 mark]

(d) (i) Explain why no sodium is produced in this experiment. __________________________________________________________________________________

[1 mark]

ACIDS & BASES

1.

Acids and bases are substances that are commonly used in everyday life.

a. (i) What is an acid?

[1 mark] (ii) What is a base?

[1 mark]

b. Give one example each of an acid and a base that is used in daily life. State the use of the acid and the base named.

[2 marks]


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c. Explain why there is a difference in the brightness of the bulbs in the electrolytic cells below.

Ethanoic acid is a weak acid. It produces low concentration of hydrogen ions

Hydrobromic acid is a strong acid. It produces high concentration of hydrogen ions

[4 marks]

d. Citric acid is a white solid. It can dissolve in two different solvents, water and propanone. The solution in water turns universal indicator paper orange-red in colour. The solution in propanone has no effect on universal indicator. Give an explanation for this observation.

Citric acid can ionize in water to show its acidic properties. Citric acid cannot ionize in propanone because it is an organic solvent.

[4 marks]


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2.

In an acid-base titration using methyl orange, 20 cm3 of dilute sulphuric acid of unknown concentration is required to completely neutralise 40 cm3 of 1.7 mol dm-3 sodium hydroxide solution.

(a) What is the colour of methyl orange in

(i) An acid solution?

(ii) An alkaline solution?

(iii) A neutral solution?

[3 marks]

(b) In the titration above, how many moles of sodium hydroxide have been used?

[2 marks]

(c) How many moles of sulphuric acid are there in 20 cm3 of dilute sulphuric acid used in the titration above?

[2 marks]

(d) What is the molarity of the dilute sulphuric acid used?

[1 mark]


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(e) Assuming sulphuric acid dissociates 100% in aqueous solution, what is the concentration of H+ ions in the dilute sulphuric acid used? Explain your answer.

[2 marks]

SALTS

1.

The figure below shows the chemical changes that occur with the carbonate of P.

(a) Identify P.

[1 mark] (b) P is heated strongly and decomposes to form solid R and carbon dioxide.

(i) Identify solid R.

[1 mark] (ii) What is the colour of solid R when it is still hot and when it is cooled?

[1 mark]


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(c) Nitric acid is added into solid P.

(i) What would you see when nitric acid is added to solid P?

[1 mark] (ii) Identify Q.

[1 mark] (iii) Describe what is observed when sodium hydroxide is added drop wise into

solution Q until in excess.

[1 mark]

(d) Potassium iodide solution is added into solution Q to form compound T.

(i) Identify T.

[1 mark] (ii) Write an ionic equation to show the reaction between solution Q and

potassium iodide.

[1 mark]

(e) Describe what happens to T when it is heated in hot water.

[1 mark]

2.

Barium chloride, copper (II) nitrate, magnesium sulphate, lead (II) carbonate (a) From the above list of salts, identify the salt which

(i) Gives off brown fume on heating.

[1 mark]


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(ii) Gives off a gas that turns limewater milky on heating.

[1 mark] (iii) Leaves a black residue after heating.

[1 mark] (iv) Releases effervescence with dilute hydrochloric acid,

[1 mark]

(b) Three of the given salts can dissolve in water.

(i) Identify the salt that does not dissolve in water.

[1 mark] (ii) Identify the salt that gives a coloured solution when dissolved in water.

[1 mark] (iii) Which of the two solutions of salts form a white precipitate when mixed

together?

[2 marks] (iv) Give the name of the white precipitate formed in (b)(iii) and write an ionic

equation for the reaction.

Name of white precipitate:

[1 mark] Ionic equation :

[1 mark]


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MANUFACTURED SUBSTANCES IN THE INDUSTRY

1.

(a) Bronze is a type of alloy that is made up of copper and other elements. It is harder than pure copper.

(i) Draw the arrangements of particles in pure copper and bronze in the spaces provided below.

Pure copper Bronze

[2 marks] (ii) Explain why bronze is harder than pure copper.

[2 marks]

(c) The followings are the information of composite material.

It is used in the manufacture of lenses.

Lenses produced have better ability to protect our eyes from harmful ultraviolet rays.

(i) Name the composite material.

[1 mark] (ii) How do the lenses protect our eyes during a sunny day?

[2 marks]


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2.

The following flow chart shows the steps involved in the manufacture of an industrial substance L and the production of fertiliser M.

(a) What is the industrial substance L?

[1 mark]

(b) Name the industrial process to produce substance L.

[1 mark]

(c) What is substance K?

[1 mark] (d) The conversion of sulphur dioxide to substance K is very slow and the percentage

of conversion is also very low. Give two ways to overcome these problems.

[2 marks] (e) What is fertiliser M?

[1 mark]

(f) Write a balanced equation for the formation of fertiliser M.

[2 marks]


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(g) (i) Sulphur dioxide can cause acid rain. Give one effect of acid rain on the environment.

[1 mark]

4.

Types of glass Composition Uses

P Silica, sodium oxide and calcium oxide.

To make glass bottles and glass windowpanes.

Borosilicate glass Silica and compound Q. To make test tubes and beakers.

Photochromic glass Compound R, compound S and copper (II) oxide

To make lenses of spectacles.

T Silica and lead (II) oxide To make prisms and lenses.

The table above shows the composition and uses of four types of glasses.

(a) (i) Give the chemical name for silica.

[1 mark] (ii) State a natural source of silica.

[1 mark]

(b) Name the type of glasses P and T in the table above

(i) P :

(ii) T :

[2 marks] (c) State the main difference between glass P and borosilicate glass.

[1 mark]


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(d) State the compounds Q, R and S in the table above.

Q :

R :

S :

[3 marks] (e) State a characteristic of the lens of the spectacles that are made from

photochromic glass.

[1 mark] (f) State a characteristic of glass T.

[1 mark]

8.

The table below shows several examples of alloys and their component elements.

Alloy Component elements

S Iron, carbon

Stainless steel Iron, K, L

Brass M, zinc

T Aluminium, copper

(a)

(i) Name alloy S and draw a labeled diagram to show the arrangement of particles in it.

[2 marks]


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(ii) Give one use of alloy S in the industry.

[1 mark]

(b) Name foreign elements K and L in stainless steel.

[1 mark]

(c) (i) Name the metal M present in brass.

[1 mark] (ii) Give one advantage of brass compared to metal M in terms of ductility and

hardness.

[1 mark] (iii) Name one object made of brass.

[1 mark]

(d) Alloy T is usually used for the construction of body frames of airplanes.

(i) Give the name of alloy T.

[1 mark] (ii) Give one property of alloy T that makes it suitable for the construction of the

body frames of airplanes.

[1 mark]


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9.

The figure below shows the flow chart for the production of ammonia gas.

(a) Explain how nitrogen and hydrogen are obtained?

(i) Nitrogen:

(ii) Hydrogen

[2 marks] (b) In what ratio does nitrogen react with hydrogen?

[1 mark] (c) (i) Name the catalyst used in the catalyst tower.

[1 mark] (ii) State the optimum temperature and pressure for the mixture of nitrogen and

hydrogen to react.

[1 mark]

(d) What is the purpose of the cooling tower?

[2 marks]


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(e) (i) State the reagent P used to convert ammonia to ammonium nitrate.

[1 mark] (ii) State a use of ammonium nitrate.

[1 mark] (iii) Write a chemical equation for the reaction between P and ammonia.

[1 mark]

GOOD LUCK FOR TRIALS

AND SPM 2014 !

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Chemistry Handout Smk Bb