Which of the following is a chemical change?
A molecule is:
the smallest particle that can exist.
the smallest particle of an element that can exist.
two or more atoms chemically joined together.
the same as an atom.
When some salt is dissolved in plenty of water, which statement is most likely TRUE about the resulting solution?
the solution becomes more concentrated the longer it is boiled.
the boiling point decreases the longer the solution is boiled.
the freezing point is higher than pure water.
the boiling point is lower than pure water.
Which method of separation is best to use for checking which ink was used in a fake cheque?
1 filtration
2 crystallisation
3 distillation
4 chromatography
Which method of separation is best to use for removing mud in muddy water?
1 Filtration
2 Crystallisation
3 Distillation
4 Chromatography
Which order of the three words matches the three substances salt, sodium, seawater ?
compound, element, mixture
mixture, compound, element
element, compound, mixture
element, mixture, compound
Which is the best way to get the salt back from some salty water?
Sieving
Using a magnet
Letting the water evaporate
Filtering
The best way to separate sand from iron filings is:
adding water and then filtering
using a magnet
filtering
sieving
Name the PROCESS you would use to obtain a sample of SOLID SALT from some sea water
Filtration
Electrolysis
Evaporation
Distillation
A boy dissolved some salt in warm water. What do we call the resulting mixture?
a filtrate
a solution
a solute
a solvent
What process would be used to obtain the solvent from a solution?
Chromatography
Which of the following would you use filtration for?
Separating the solute from a solution
Making a solution more concentrated
Separating a suspension from a solution
Separating the solvent from a solution
Put the following processes into the correct order if you wished to obtain pure salt from rock salt.
1. Evaporate the water 2. Dissolve the salt in water 3. Filter the solution
1. Dissolve the salt in water 2. Filter the solution 3. Evaporate the water
1. Filter the solution 2. Dissolve the salt in water 3.Evaporate the water
After filtering a mixture what do we call the liquid that drips through the filter paper?
Distillate
Filtrate
Residue
Crude oil can be separated into different substances using what method of separation?
Fractional distillation
Simple distillation