Topic 3 States of matter, separating and purifying Flashcards
1 What are the three states of matter?
solid, liquid, gas
2 In which state are the particles arranged regularly?
solid
3 In which state do particles move quickly in all directions?
gas
4 What state change happens when a substance melts?
solid to liquid
5 What state change happens when a substance condenses?
gas to liquid
6 In general, which state of matter has particles with the highest energy?
gas
7 What is the melting point of water in °C?
0
8 What is the boiling point of water in °C?
100
10 The melting point of sodium is 97.7 °C. What is the state of sodium at 25.0 °C?
solid
21 What is a mixture?
different elements and/or compounds that are not chemically joined together
22 Which is a mixture, air or water or both?
air
23 Which of a mixture or a pure substance has a fixed composition?
pure substance
27 Is a material that melts over a range of temperatures likely to be a mixture or a pure substance?
mixture
28 Give one safety precaution to take when heating substances.
any suitable, tie hair back, tuck tie in, wear safety goggles
29 What do we call the change of state from a liquid to a gas?
evaporation
30 Name a mixture that could be separated by filtration?
any suitable e.g. sand and water
36 How can you get salt from salty water?
evaporate the water; crystallisation
37 What is the scientific name for a mixture like salty water?
solution
38 What is the term used for the liquid in a solution?
solvent
39 What is the term for the substance that has dissolved in the solution?
solute
40 How can you identify a pure substance on a chromatogram?
only one spot/colour
45 How can we separate an insoluble solid from a liquid?
filtration
46 What word describes the clear liquid that comes through the filter paper?
filtrate
48 What process takes place when a liquid turns into a gas?
evaporation
49 What process takes place when a gas turns into a liquid?
condensation
53 Which of these is soluble in water - sand or salt?
salt
54 What separation method is used to remove insoluble solids from a liquid?
filtration
56 What separation method could you use to separate water from ink?
distillation/simple distillation
57 Name the two state changes involved in distillation.
boiling/evaporating, condensing
59 What gas with a sharp smell is used to kill bacteria in swimming pool water?
chlorine
60 Why does seawater taste salty?
it contains dissolved salt