Revision Sheets Chemistry 97.

A : Number of mole, mass and particle Mole X Molar Substance Mass = mass NaCl 0.02 mole KOH 1.5 mole MgO

Number of particle = mole x NA

Volume = mole x molar volume (22.4 dm3)

80 g

PbCO3

0.04 mole

CO2

2.2 g

Cu(NO3)2

2.5 mole

NaOH

70 g

C : RAM / RMM Substance Relative Atomic Mass (RAM or Mr)

Substance

NaCl

Cu(NO3)2

KOH

NaOH

MgO

Zn(NO3)2

PbCO3

Ca(OH)2

CO2 D : Chemical Formulae for Ions Chemical Name of cation / Name of cation / positive ion Formula positive ion + Hydrogen Silver H Lithium Iron (II) Sodium Iron (III) Potassium Lead (II) Calcium Lead (IV) Magnesium Ammonium Aluminium Stanum (II) Zinc Stanum (IV) Copper (I) Copper (II) E : Chemical formula for Ionic Compound Name Ionic Formula Hydrochloric acid HCl Sulphuric acid Nitric acid Ammonia gas Chlorine gas Hydrogen sulphide gas E

Relative Atomic Mass (RAM or Mr)

NH3 Chemical Formula

Name of anion / negative ion chloride bromide iodide hydroxide nitrate carbonate sulphate oxide

Chemical Formula

phosphate

Name Sodium hydroxide Potassium hydroxide Barium hydroxide Sulphur dioxide gas

Ionic Formula

Nitrogen dioxide gas Sulphur trioxide gas

Write a balance chemical and ionic equation using symbol and formula Reactant Balance chemical equation

1. Hydrochloric acid + Sodium hydroxide 2. Sulphuric acid + Barium hydroxide 3. Nitric acid + Potassium hydroxide 4. Hydrochloric acid + Magnesium (s) 5. Hydrochloric acid + sodium carbonate 6. Sulphuric acid + Copper (II) carbonate 7. Sulphuric acid + Ammonium carbonate 8. Nitric acid + Lead (II) carbonate 9. Hydrochloric acid + Zinc oxide 10. Sulphuric acid + Copper (II) oxide

HCl (aq) + NaOH (aq)

NaCl (s) + H2O (l)

Element 1 (Alkali metals) 1. Common characteristic i) Good conductor of heat and electricity ii) Gray in color with silvery and shiny surface when freshly cut. iii) Reactive alkali metal iv) Ability to lose electron to achieve a stable electron configuration Elements

Symbols

Electron configuration

Rubidium Caesium Francium

Rb Cs Fr

2.8.18.8.1 2.8.18.18.8.1 2.8.18.32.18.8.1

Density

Size atom

Melting point / Boiling point

Reactivity

All alkali metal have one valence electron. Therefore they will have similar properties

The atomic number of shells occupied increases. The distance between the outermost shell occupied electrons with nucleus becomes further. So the size increasing down the group. As the atomic size increases, the force of attraction between metal become weaker. Thus, less energy needed to overcome the weak force of attraction during melting and boiling.

• Group 1 will tend to lose 1 e to form +1 charge ion to achieve the stable duplet (2) or octet (8) electron arrangement. Example : a) Li

b) Na

Li+ + eNa+ + e-

c) K • As go down the group, the size is increasing. The valence electron become further from nucleus. Hence, the force of attraction between valence electron and nucleus become weaker. As the result, it is easier to lose 1 electron to achieve duplet or octet electron arrangement. • Can form an alkaline metal hydroxide and hydrogen gasses. 2 Li (s) + 2 H2O (l)

2 LiOH (aq) + H2 (g)

• Can form an metal oxide 4 Li (s)

+ O2 (g)

2 Li2O (s)

Element 18 ( noble gases) 1.

Common characteristic i) Not reactive (inert gases) ii) Have stable electron configuration (duplet =2 or octet = 8) iii) Monatomic gasses (He, Ne, Ar, Kr) iv) Have low melting and boiling point compare to other alkali metal because they are held together by a weak Van der Waals force of attractions.

Elements

Krypton Xenon Radon

Symbols

Kr Xe Rn

Electron configuration

Size atom

Density

Melting point / Boiling point

2.8.18.8 2.8.18.18.8 2.8.18.32.18.8

Reactivity

Not chemically reactive

Noble gasses have 2 or 8 valence electron

Atomic size increasing because the number of shell occupied electron is increasing The increase in relative atomic mass is more than the increase in atomic size down the group.

b.p and m.p increasing down the group. The number of shell occupied electron is increasing, thus the van der walls force between the outermost electron with nucleus become stronger. Therefore more heat energy is required to overcome the force during melting and boiling.

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Elements in group 18 are not chemically reactive. This is because they have reached the stable electron configuration. A stable electron configuration is having 2 electron valence (duplet) or 8 electron valence (octet) • • • • • •

Helium : Neon : Argon : Krypton : Xenon : Radon :

2 2.8 2.8.8 2.8.18.8 2.8.18.18.8 2.8.18.32.18.8

These electron arrangements are very stable. They will not gain , lose or share electrons with other elements. Therefore, they are not chemically reactive