Q1  A


Q2  C

S有six outermost shell electrons = 差2粒positvie electrons from Li

Q3  D

只有group 1/ 2先會react with water vigorously,仲要出到YO即係group 1

period 數目= number of  outermost shell electrons

Q4 C (此為第三式)

Mg + water vapour = magnesium oxide and hydrogen gas

Related Knowledge : 金屬活潑程度(高至低) 鉀鈉鈣鎂鋁鋅鐵鋅鉛 氫 銅汞銀鉑金

 一式無尾三 (一式即metal + oxygen) ; 二式得頭三 (二式即係同水反應) ; 鎂鋁鋅鐵三 (三式為與water vapour反應); 高氫者會酸 (活潑程度高過氫的,會與酸react)

Q5 B

如果係plating包住晒一個metal,咁就必定係prevent from air; 如果個plating有破損,入面既metal接觸到oxygen時,先要諗有無sacrificial protection.

Q6 B

Q7 A

此為四式,高氫者會酸 : Zn reacts with acid,所以唔係C同D; acid + water = H+

Q8 A

Reactivity series: Hydrogen > Copper (因為高氫者才會酸,所以C同D都錯)


Q9 C

1mol C6H12 = 18mol carbon and hydrogen atoms

9 mol O2 = 18mol oxygen atoms

Q10 B

需要背;或者可以咁記:catalytic converter會為chemicals reduction and oxidation;nitrogen oxides = nitrogen and oxygen ( both harmless)

carbon monoide and unburnt hydrocarbons = carbon dioxide (harmless)

Q11 A

overall compound's charge = 0

NF3 =  N(所以呢到係+3)     F3 (-3)

NaNH3 = 首先諗左知既atom先,Na = +1 / H = +1,但係H3 所以+3 ,因為compund's charge =0 ,所以N = -3

Q12 B

首先,電路圖係長正短負。所以Rod I 係positive,Rod IV係negative; 而同一器皿入面會係相反,即Rod II 係negative

Ions由more reactive to less reactive,即係由右去左。Mg ions去了左邊,會attach to negative rod,which is Rod II

Q13 C

係Group 7 既gas入面,the reactivity decreases along the group。位於上面的gas,可以replace下面的oxide。

Q14 D

redox reaction = have change in oxidation number

最簡單諗法:compound入面的ion 一定有oxidation number,不過一粒atom既oxidation number係0,所以a,b,c 都一定有redox

Q15 B

係recharge,咁一定會係equation既左邊有electrons,所以會係B or D

discharge : Negative electrode(Cd) will lose electrons

recharge   : (Cd) gains electrons

Q16 A

atom時more reactive = compound時more stable。四樣野都係同hydrogen反應,所以睇返4隻gases 邊個最reactive就得。

Q17 C

petroleum separation :  fractional distillation

Petroleum is a mixture of chemicals

Q18 A

vinegar is weak acid (~3) ; pH=1 hydrochloric acid from stomach lining (strong acid)

sugar is not a base

Q19 C

Household cleaner = Ammonium hydroxide

sodium is not corrosive, but explosive

Q20 D

oxidation number 下降= reduction

變左Ion 只係關electrons時

Pb is group 4 element,走左2粒電子都仲有2粒係入面,所以呢shell都係一樣

Q21 C

molecule shape要睇bond pair and lone pair

N同P/H同F既outermost shell electrons 都係一樣,所以個shape都係一樣

Q22 D

you have to remember

Q23 C

electrolyte : dilute (1-2 M) sulphuric acid

anode : Aluminium

cathode : (usually aluminium is also used as the cathode in laboratory)

AO CR : anode oxidation; cathode reduction

Anode:  4Al + 3O2 → 2Al2O3

Q24 D

1st : standard enthalpy change of formation = varies from compounds

2nd : 如果noble gas變左compound = 咁一樣係noble gas element more stable

Q25 C

2 Mg + 2HCl → MgCl + H2

0.03mol    0.02dm3



Mg is in excess

H2 = 0.01 mol

The initial rate is faster

Q26 B

Temperature increases = rate of reactions increase

Q27 D

Group 7 elements have colours

Q28 C

Functional group: but-1-ene (alkene) ; butan-1-ol (alcohol)

Q29 C

Fumaric acid +  Maleic acid + the one has two COOH groups

Q30 D

electronegativity : 吸電子的能力

愈上愈右愈高 i.e F is the highest

Q31 A

It is used to make rope

repeating unit of nylon-6,6

Q32 B

Q33 D

HCl is strong acid while CH3COOH is weak acid

contact surface area愈大,rate of reaction 愈快

Mn02 is catalyst

Q34 B

有gas = 可以用volume of gas

有顏色的ion = 可以用color intensity

有solid power = 先可以用turbidity

Q35 A

soap decreases         surface tension of water

Q36 A

P4O10 + 12NaOH → 4Na3PO4 + 6H2O

When dissolved in water, nonmetal oxides form acids:

P4O10 + 6 H2O = 4 H3PO4; H3PO4 is an acid = P4O10 is an acidic oxide

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