Hi Austin,I haven't seen all the November papers. When the IB does release the exam papers through Follet IB Store they tend to have some...
Critically analysing IB questions for errorsHave you had a chance to look at the papers from November? I don't think these are officially released yet, but there is one very obvious mistake in one of the paper 2 questions.
Critically analysing IB questions for errorsHi Joseph, 0.025 mol of CuSO4.5H2O contains 5 x 0.025 mol of water, i.e. 0.125 mol of water. The mass of 0.125 mol of water = 0.125 x 18.02 = 2.25 g so students need to weigh out 47.75 g of water to bring the total mass of water...
Enthalpy changesI have a question about determining the enthalpy change for the hydrated copper (II) sulfate in water. You state: Note that 50 g water less 5 x 0.025 mole of water which comes from the hydrated salt should be weighed out. To...
Enthalpy changesHello Dave, It's true that "the IB now uses K for the equilibrium constant" - well sometimes anyway - as it still uses Ka, Kb and Kw which are all equilibrium constants and had...
R2 EquilibriumHi Mr. Neuss. I was under the impression that we were using K now, instead of Kc for the equilibrium constant ...
R2 EquilibriumJudith Yes, it can be tricky to navigate this. The teacher support material does indeed state: "When the final percentage uncertainty is greater than or equal to 2%, it should be given to one significant figure." That applies to stating...
Error & uncertaintyIn the teacher support material on uncertainties they say that only 1 sf for uncertainties more than 2 % and never more than 2 sf. I have usually gone for 1sf as the uncertainties on equipment is usually 1sf, I am unsure now when 1 or...
Error & uncertaintyHello Lucy - Happy New Year. I've fixed the link now. It takes you to an AHL data-based question on iron pentacarbonyl which you will need to give your HL students access to.
S2.2 (AHL) The covalent model (1)
Austin
Ah, yes. Obviously I've read that blog post - didn't realise it was for November. I'll comment over there.
Critically analysing IB questions for errors