Mixing,Dissolving and Separating- Chemistry Flashcards
What is a pure substance in chemistry?
A substance that only contains one type of atom or compound
What is an impure substance in Chemistry?
A substance that contains more than one substance (element or compound), forming a mixture
Are the substances in the mixture Chemically joined?
No, which makes them separable
How do you use Chromatography?
For this example we are using the pigments in ink.The sample mixture is loaded on a pre-marked line at the bottom of a piece of chromatography paper and dipped into solvent. As the solvent moves up the paper it take sthe dissolved pigments with it. Since the pigments have different solubilities they travel at different speeds and so separate. the most soluble pigments move the furthest; less soluble pigments move less far.
What does filtration do?
Filtration separates an insoluble solid from a liquid by passing the solid/liquid mixture through the filter paper
What is the liquid that passes through the filtration paper called?
The Filtrate
What does evaporation do?
Evaporation is used to remove the liquid part of a mixture and collect the dissolved solid.
How do you use Evaporation?
The mixture is placed in a suitable container (e.g. a watch glass) and heated, sometimes using a Bunsen burner
What does the law of conservation of mass state?
That in any physical change or chemical reaction the mass after change will be the same as the mass before the change.
What properties does a solid have?
A solid will vibrate and hold in a solid lattice
What properties does a liquid have?
A liquid’s molecules move freely but are packed close together with at least 50% touching
What properties does a gas have?
All molecules in a gas are separate and move at high speeds
What is combustion?
Combustion is the reaction between a fuel and oxygen
What are generally waste products when the fuel is hydrocarbon?
Carbon dioxide and water are waste products from the reaction
how is energy released?
energy is released as heat and light
