Chemistry Revision Igcse

Front 1

What is an element?

Back 1

An ELEMENT is a pure substance made up of only one type of atom

Front 2

What is a compound?

Back 2

A COMPOUND is a chemical combination of two or more different elements.

Front 3

What is a mixture?

Back 3

MIXTURE is a material made up of at least two substances which may be elements or compounds. They are usually easily separated by physical means e.g. filtration, distillation, chromatography etc.

Front 4

what is a chemical equation?

Back 4

CHEMICAL EQUATION is an expression in words or symbols that describes precisely a particular chemical change

Front 5

What is filtration?

Back 5

using a filter paper or fine porous ceramic to separate a solid from a liquid. It works because the tiny dissolved particles are too small to be filtered BUT any insoluble 'non-dissolved' solid particles are too big to go through!

Front 6

what is evaporation?

Back 6

means a liquid changing to a gas or vapour. In separation, its removing the liquid from a solution, usually to leave a solid. It can be done quickly with gentle heating or left out to 'dry up' slowly. The solid will almost certainly be less volatile than the solvent and will remain as a crystalline residue.

Front 7

What is crystallization

Back 7

Crystallisation can mean a liquid substance changing to its solid form. However, the term usually means what happens when the liquid from a solution has evaporated to a point beyond the solubility limit. Then solid crystals will 'grow' out of the solution because the solution is too concentrated for all the solid to remain dissolved at that temperature. Crystallisation is often done from a hot concentrated solution, because most substance are more soluble the hotter the liquid. Consequently on cooling a hot concentrated solution, crystals form as the solubility gets less and less.

Front 8

what does 1 mole equal???

Back 8

6.02 x 10^23 anything

Front 9

Cooling Curve steps (at a constant rate), from top to bottom. Note: Where the plateaus are where the PE decreases, and where the charts decrease is where the KE decreases

Back 9

gas, condensation, liquid, freezing, solid

Front 10

solid→liquid

Back 10

melting

Front 11

solid→gas

Back 11

sublimation

Front 12

liquid→solid

Back 12

freezing

Front 13

liquid→gas

Back 13

vaporization

Front 14

gas→liquid

Back 14

condensation

Front 15

gas→solid

Back 15

deposition

Front 16

Molarity formula:

Back 16

M = moles of solute/liters of solvent

Front 17

Molarity formula:

Back 17

m = moles of solute/kilograms of solution

Front 18

Saturated Solution

Back 18

A solution that contains the maximum amount of dissolved solute

Front 19

REDOX Reactions involve the transfer of ____; If the oxidation number changes from the reactant to product, then the reaction is REDOX

Back 19

electrons

Front 20

Oxidation is the ____ of electrons; where the oxidation number goes up

Back 20

loss

Front 21

Reduction is the ____ of electrons; where the oxidation number goes down

Back 21

gain

Front 22

The five things that speed up a chemical reaction are ______

Back 22

temperature; concentration; catalyst; surface area; nature of the reaction

Front 23

Volume increases favours ____

Back 23

favors the reaction with more moles

Front 24

Pressure decreases favours _____

Back 24

favors the reaction with more moles

Front 25

Standard Temperature and Pressure in the following order: degrees Celsius, Kelvin, mm Hg, torr, atm, and kPa

Back 25

0°C, 273 K, 760 mm Hg, 760 torr, 1 atm, 101.3 kPa

Front 26

Energy of Wave
Wave Relation
Coulomb's Law

Back 26

E = h v
c = \lambda v
F_e = k_e\frac{Q_1Q_2}{r^2}
Symbol Meaning Symbol Meaning
E energy c speed of light
v frequency \lambda wavelength
Q charge r distance
k_e Coulomb's constant h Plank's constant