Topic 2: Elements, Compunds and Mixtures Flashcards
What is the definition of an element?
An element is a substance that consists of only one type of atom. Elements cannot be broken down into simpler substances by chemical means
What is the definition of a compound?
A compound is a substance that consists of two or more different elements chemically joined together
What is the definition of a mixture?
A mixture consists of two or more substances that are usually easy to separate
Aluminium: Element, Compound or Mixture?
Element
Sodium chloride (salt): Element, Compound or Mixture?
Compound
Carbon dioxide: Element, Compound or Mixture?
Compound
Lead: Element, Compound or Mixture?
Element
Rock salt: Element, Compound or Mixture?
Mixture
Sugar solution: Element, Compound or Mixture?
Mixture
What does soluble mean?
A solid that dissolves easily in a liquid solvent eg. Sugar, salt
What does insoluble mean?
A solid that does not dissolve easily in a liquid solvent eg. Sand
What does solute mean?
A solid that dissolves. This is a substance that changes its state during a dissolving process
What does solvent mean?
This is a substance that does not change its state during a dissolving process
What does solution mean?
A mixture containing the solute and solvent
Solution = solute + solvent
What does residue mean?
Solid particles trapped in filter paper eg. Sand
What does filtrate mean?
Liquid particles that pass through the filter paper
What does distillate mean?
The liquid that condenses during distillation and is collected
What does miscible mean?
A liquid that mixes easily in another liquid eg. Ethanol and water
What does immiscible mean?
A liquid that does not mix easily in another liquid eg. Oil and water
What are the benefits of mass Spectroscopy?
> Fast analysis
Results can be linked to database to
identify substance
What are the drawbacks of using Mass Spectroscopy?
> Expensive equipment
Presence of isotopes leads to more than
one peak
What are the benefits of using HPLC?
> Fast
Accurate
Use only minute samples
What are the drawbacks of using HPLC?
> Sample must be a liquid
> Expensive
What is the equation for working out relative atomic mass?
Mass x abundance / total abundance
eg. (20 x 10) + (80 x 11) / 100 < (always the
total)
