Basic Chemistry

Question 1

Mixtures

Answer 1

Two or more elements/compounds mixed together but not chemically bonded

Question 2

Why do we need to separate mixtures?

Answer 2

To make them pure.

Question 3

What are the different methods used to separate mixtures?

Answer 3

-distillation
-filtration
-evaporation
-crystallisation
-magnets
-chromatography

Question 4

Compound

Answer 4

Two or more elements chemically bonded together.

Question 5

Element

Answer 5

A substance made up of one type of atom and it cannot be broken down into anything simpler by chemical means (which makes it a pure substance)

Question 6

Molecule

Answer 6

-group of two or more atoms of the same or different elements that are chemically bonded together.
e.g.two atoms of hydrogen and one atom of oxygen chemically bonded to make a molecule of water

Question 7

Homogenous mixture

Answer 7

Particles distributed uniformly/evenly

Question 8

Heterogeneous mixture

Answer 8

Particles distributed non-uniformly/unevenly

Question 9

Filtrate

Answer 9

-liquid you call after filtering

Question 10

Residue

Answer 10

-substance left on the filter paper after filtering

Question 11

Soluble

Answer 11

Something you can dissolve in water

Question 12

Solvent

Answer 12

any substance, usually liquid, which is capable of dissolving one or several substances, thus creating a solution.

Question 13

Solution

Answer 13

-homogenous mixture of 2+ substances

Question 14

Solute

Answer 14

-substance that can be dissolved into a solution by a solvent

Question 15

Saturated

Answer 15

Solution in which no more solids can dissolve at the temperature

Question 16

Miscible

Answer 16

Liquids that mix together

Question 17

Immiscible

Answer 17

Liquids that mix together and separate into layers

Question 18

Filtration

Answer 18

-used to separate an insoluble solid from a liquid
(e.g. sand & water)
-mixture is poured from a funnel (which contains a piece of filter paper)
-the liquid passes through the paper whereas the solid remains on the paper
page 3 in ur book

Question 19

Evaporation

Answer 19

-used to separate a dissolved solid from the solvent it is in (e.g. salt & water)
-mixture is placed in an evaporating dish and heated until the solvent has evaporated/boiled
-this leaves the solid in the evaporating basin alone
page 4 in ur book

Question 20

Distillation

Answer 20

-used to separate the solvent from the solution (e.g. pure water and sea water)
-mixture is heated in a round bottom flask and the solvent boils
-vaporised solvent passes through a water-cooled condenser where it cools and condenses
-solvent is moved into a container away from the original solution
page 4 in ur book

Question 21

Paper chromatography

Answer 21

-used to separate mixtures of substances dissolved in a solvent
-piece of chromatography paper, with the mixture on, is placed upright in a beaker so that the bottom of the paper is in the solvent
-over time the solvent soaks up the paper
-the substances move up the paper at different speeds and so are separated
page 4 in ur book

Question 22

Magnetism

Answer 22

-used to separate magnetic materials from non-magnetic ones (e.g. iron fillings from sand)
-mixture is placed on a conveyor belt that passes under a magnet
magnetic materials are attracted to the magnet and are lifted off the belt
-non-magnetic materials continue to move along the belt and are collected separately
page 5 in ur book

Question 23

Separating Funnel

Answer 23

Glass container with a tap used to separate immiscible fluids