1
Q
Heating in a crucible?
A
1) weigh empty crucible and lid
2) add magnesium ribbon to crucible and reweigh
3) heat strongly with bunsen burner for couple of mins
4) lift lid couple of times to allow bit of O2 in but don’t let MgO escape
5) allow to cool then weigh crucible + contents again
6) reheat crucible again + reweigh until get a constant mass
2
Q
Why do we need to reheat the crucible multiple times?
A
to ensure all the magnesium has reacted + that the reaction is complete
3
Q
How do I draw a gas syringe?
A
- first draw the outline of a flask and then the syringe
- place the nozzle into the flask and draw a bung around it to show no gas escaping
- also include lines on syringe to show measurement can happen
4
Q
What are common errors with gas syringes?
A
- the gas escapes before the bung has been inserted
- the syringe sticks
