Pure substances, mixtures and separations

Question 1

a pure substance which cannot be split into simpler substances by any chemical process

Answer 1

element

Question 2

how many elements are there (csec)

Answer 2

103 elements

Question 3

compound

Answer 3

a substance containing two or more different types of element bonded together chemically in fixed proportions and in such a way that their properties are changed

Question 4

mixture

Answer 4

a mixture consists of two or more substances combined together physically

Question 5

techniques used depends on the …….. of the components

Answer 5

properties

Question 6

Two main classifications of mixtures:

Answer 6

heterogeneous mixture and homogeneous mixtures

Question 7

mixtures can also be classified as:

Answer 7

solution, suspension and colloid

Question 8

__________is formed when the solute is completely dissolved in the solution e.g. sugar and water

Answer 8

solution

Question 9

______________ is a homogeneous mixture

Answer 9

solution

Question 10

The _______ is the substance to be dissolved

Answer 10

solute

Question 11

The ________ is the substance doing the dissolving

Answer 11

solvent

Question 12

solution in which the solvent is water are known ___________

Answer 12

aqueous solutions

Question 13

a saturated solution

Answer 13

is a solution in which the solvent cannot dissolve any more solute at a particular temperature, in the presence of undissolved solute

Question 14

___________ is a heterogeneous mixture that contains solid particles that do not dissolve

Answer 14

suspension

Question 15

homogeneous mixture

Answer 15

is a uniform mixture that has the same composition and properties throughout the mixture

Question 16

heterogeneous mixture

Answer 16

is a non-uniform mixture where it is possible to distinguish the component parts from each other

Question 17

A ________ is a heterogenous mixture in which minute particles of one substance are dispersed in another substance, which is usually a liquid

Answer 17

colloid

Question 18

_____________ is used to separate a liquid from a suspended or settled solid

Answer 18

filtration

Question 19

__________ is used to separate and retain the solid solute from a solution if the solute does not decompose on heating or contain water of crystallisation

Answer 19

evaporation

Question 20

___________ is used to separate and retain the solid solute from a solution, especially if the solid contains water of crystallisation

Answer 20

crystallisation

Question 21

__________ is used to separate two immiscible liquids

Answer 21

separating funnel

Question 22

Immiscible liquids are ….

Answer 22

liquids which do not mix

Question 23

_________ is used to separate solutes, usually coloured, present in a solution, e.g. dyes in black ink, pigments in chlorophyll

Answer 23

paper chromatography

Question 24

__________ is used to separate and retain a solid which sublimes from a mixture of solids

Answer 24

sublimation

Question 25

used to separate and retain the solvent from the solution

Answer 25

simple distillation

Question 26

________ is used to separate two miscible liquids which have different boiling points

Answer 26

fractional distillation

Question 27

miscible liquids are

Answer 27

liquids which mix completely