IGCSE化学Chemistry

IGCSE Chemistry复习，内容有quantitative chemistry、Atomic structure and the periodic table、Kinetic particle theory、bonding and structure

Chemistry C1-4

quantitative chemistry

Relative atomic mass & Calculations according to chemicla formula

laws of constant composition: compounds are made up of fixed proportions of elements

relative atomic mass is the average mass of the isotopes of an element compared to 1/12 of C-12 atom

calculate Mr

relative molecular mass

relative formula mass

calculate the elemental mass ratio in the compound

elemental mass=ram of element(Ar)*number of atoms 元素质量=相对原子质量*原子个数

Calculate the percentage by mass of an element

The percentage by mass of an element in a compound is sometimes known as the percentage composition

产率

产率(persantage yield/%yield)是指在化学反应中，某种物质的实际产量与理论产量的比值

calculating moles & moles and compound

amount of substance/number of moles

a mole of substance is the amount that contains as many elementary units as the number of atoms in 12g of C-12(containing 6.02*10^23)

符号: n

单位: mole, 符号: mol

意义：表示有一定数目的粒子的集合体

阿伏伽德罗常数(the Avogadro constant)

定义: 1mol任何粒子含有的粒子数

数值：1mol 任何粒子所含的粒子与0.0012kg的C-12中所含原子数相等，即NA约等于6.02*10^23

符号: NA

单位: mol^-1

表达式: NA约等于6.02*10^23

1mol粒子=NA个粒子 约等于 6.02*10^23个粒子

公式

N＝n · NA

n=N/NA

摩尔质量(molar mass)

定义: 单位物质的量的物质所具有的质量

符号：Mm

单位：gmol^-1 or g/mol

数值: l mol任何粒子或物质的摩尔质量以g/mol为单位时，其数值等于该粒子的相 对原子（分子）质量。

公式

m=N*Mm

n=m/Mm

moles and gases & moles and equation

factor to affect the volume

number of particles

size of particle

 distance between particles

阿伏伽德罗定律(Avogadro's law)

Avogadro's law states that: equal volumes of gas, at the same temperature and pressure, contains the same number of molecules

at room temperature and pressure(RTP)， one mole of any gas has a volume of 24L, this quantity alson known as molar mass volume(Vm)

room temperature=25摄氏度

moalr gas volume(气体摩尔体积)

定义：单位物质的量的气体所占有的体积，叫做气体摩尔体积

符号：Vm

单位：L·mol^-1（或L/mol）

数值

在室温和大气压（101 kPa）下，气体摩尔体积为24L/mol

在标准状况（温度为0℃，压强为101 kPa）下，气体摩尔体积为22.4L/mol

公式

V=n*Vm

n=V/Vm

bonding and structure

ionic bonding

name of ionic compounds

ionic compunds=positive ion(metal ion)+negative ion(non-metal ion)

formulae of ionic compund

eg: Al3+ & O2-

step1: speculate the formula is AlnOm

step2: net change=n*(+3)+m*(-2) =n/m=2:3

cross over method

prooerties of ionic compounds

they are usually solid at room temperature

they are usually hard substances

they mainly dissolve in water

they usually conduct electricity when in the molten state or in aqueous(water) solution

they usually cannot conduct electricity when solid

covalent bonding

covalent bond is a chemical bond formed by sharing of one or more pairs of electrons between two atoms

properties of covalent compounds

covalent structure

giant molecular

regular arragement of atoms by covalent bond

metallic bonding

metal bonding

metallic bond is the strong electrostatic force between the metal positive ions and delocalised electrons

metal atoms can off-load the outer shell electrons and become metal positiove ion

The outer dhell electrons are free to move throughout the lattice. They are called delocalised electron

three factors that can influence the metallic bond strenth

positive charge on the metal ions

number of mobile electrons per atom

size of metal ion(radius of ions)

Giant covalent structure.

Diamond.

Graphite

siliconl dioxide.

Kinetic particle theory

Solid liquid gas.

Changes of state

Meaning point

Pressure of gas

Solution

Diffusion

Atomic structure and the periodic table

Atom

Nucleus

Proton

Neutron

Electron

The Periodic Table

Chemistry C1-4

quantitative chemistry

Relative atomic mass & Calculations according to chemicla formula

laws of constant composition: compounds are made up of fixed proportions of elements

relative atomic mass is the average mass of the isotopes of an element compared to 1/12 of C-12 atom

calculate Mr

relative molecular mass

relative formula mass

calculate the elemental mass ratio in the compound

elemental mass=ram of element(Ar)*number of atoms 元素质量=相对原子质量*原子个数

Calculate the percentage by mass of an element

The percentage by mass of an element in a compound is sometimes known as the percentage composition

产率

产率(persantage yield/%yield)是指在化学反应中，某种物质的实际产量与理论产量的比值

calculating moles & moles and compound

amount of substance/number of moles

a mole of substance is the amount that contains as many elementary units as the number of atoms in 12g of C-12(containing 6.02*10^23)

符号: n

单位: mole, 符号: mol

意义：表示有一定数目的粒子的集合体

阿伏伽德罗常数(the Avogadro constant)

定义: 1mol任何粒子含有的粒子数

数值：1mol 任何粒子所含的粒子与0.0012kg的C-12中所含原子数相等，即NA约等于6.02*10^23

符号: NA

单位: mol^-1

表达式: NA约等于6.02*10^23

1mol粒子=NA个粒子 约等于 6.02*10^23个粒子

公式

N＝n · NA

n=N/NA

摩尔质量(molar mass)

定义: 单位物质的量的物质所具有的质量

符号：Mm

单位：gmol^-1 or g/mol

数值: l mol任何粒子或物质的摩尔质量以g/mol为单位时，其数值等于该粒子的相 对原子（分子）质量。

公式

m=N*Mm

n=m/Mm

moles and gases & moles and equation

factor to affect the volume

number of particles

size of particle

 distance between particles

阿伏伽德罗定律(Avogadro's law)

Avogadro's law states that: equal volumes of gas, at the same temperature and pressure, contains the same number of molecules

at room temperature and pressure(RTP)， one mole of any gas has a volume of 24L, this quantity alson known as molar mass volume(Vm)

room temperature=25摄氏度

moalr gas volume(气体摩尔体积)

定义：单位物质的量的气体所占有的体积，叫做气体摩尔体积

符号：Vm

单位：L·mol^-1（或L/mol）

数值

在室温和大气压（101 kPa）下，气体摩尔体积为24L/mol

在标准状况（温度为0℃，压强为101 kPa）下，气体摩尔体积为22.4L/mol

公式

V=n*Vm

n=V/Vm

bonding and structure

ionic bonding

name of ionic compounds

ionic compunds=positive ion(metal ion)+negative ion(non-metal ion)

formulae of ionic compund

eg: Al3+ & O2-

step1: speculate the formula is AlnOm

step2: net change=n*(+3)+m*(-2) =n/m=2:3

cross over method

prooerties of ionic compounds

they are usually solid at room temperature

they are usually hard substances

they mainly dissolve in water

they usually conduct electricity when in the molten state or in aqueous(water) solution

they usually cannot conduct electricity when solid

covalent bonding

covalent bond is a chemical bond formed by sharing of one or more pairs of electrons between two atoms

properties of covalent compounds

covalent structure

giant molecular

regular arragement of atoms by covalent bond

metallic bonding

metal bonding

metallic bond is the strong electrostatic force between the metal positive ions and delocalised electrons

metal atoms can off-load the outer shell electrons and become metal positiove ion

The outer dhell electrons are free to move throughout the lattice. They are called delocalised electron

three factors that can influence the metallic bond strenth

positive charge on the metal ions

number of mobile electrons per atom

size of metal ion(radius of ions)

Giant covalent structure.

Diamond.

Graphite

siliconl dioxide.

Kinetic particle theory

Solid liquid gas.

Changes of state

Meaning point

Pressure of gas

Solution

Diffusion

Atomic structure and the periodic table

Atom

Nucleus

Proton

Neutron

Electron

The Periodic Table