finding the % water of crystallisation in hydrated iron(II) sulfateWatch
1. Using a balance that weighs to two decimal places, weigh a crucible. Add between 1.30 – 1.50 g of hydrated iron II sulphate crystals. Record the masses.
2. Place the crucible containing the hydrated iron(II) sulphate crystals on the pipe-clay triangle and gently heat for about two minutes. The heating should be carried out in either a fume cupboard or a well-ventilated room.
3. Allow to cool and weigh the crucible and the iron(II) sulphate.
4. Repeat steps 2 and 3.
5. Record all of the masses.
basically the aim was to find out what x was for this equation:
these were my results from the experiment:
crucible weight + iron sulfate before = 25.77g (i used exactly 1.5g iron sulfate)
which led me to work out ther is 44% water
moles=mass/Mr was 0.037
how do i work out what the value of x is from this???
From their data you should be able to work out the mass of water that was lost during heating. With a bit of work, you can work out the mass of the iron(II) sulfate after heating (by subtracting off the mass of the crucible).
You can convert both of these masses to amounts (in mol).
You can then simplify the ratio of these two amounts, which will give you the simplest whole number ratio of iron(II) sulfate:water, i.e. the # of WoC.
Have a go, and someone will confirm your answer (if you want me to check, please reply to me and it'll pop up as an alert)