C2.1.3 - Pure and impure substances Flashcards
1
Q
What is a pure substance?
A
A substance that consists of only one element or compound
2
Q
What is an impure substance?
A
A material consisting of 2 or more different elements or compounds. Mixtures are an example of this
3
Q
What is an alloy?
A
A mixture of a metal with one or more elements
4
Q
Why is mixture of gold used instead of pure gold in jewellery?
A
Pure gold is very soft so adding other elements such as copper make it harder
5
Q
What is the melting point of an impure substance like?
A
Its melting point is less than that of the pure substance
It often melts over a range of temperatures, not just one temperature
6
Q
What is air a mixture of?
A
Nitrogen, oxygen and other substances
7
Q
What is the melting point of iron?
A
1538 Celsius
