sum of enthalpy changes around a Hess cycle = 0
Give every cycle arrow its sign; electron affinity is often already negative.
Do each calculation on paper first, then reveal the mark scheme and tick the marks you actually earned — the same way you should mark past papers.
[4 marks]
Total for this question: 4
Do the calculation on paper first — then mark it.
Exam tip: Write one algebraic Hess equation from gaseous atoms and ions to the solid before substituting values.
Calculations are the most trainable marks in chemistry
They come up every paper and reward a clean method. Send me one you keep dropping marks on. Free intro call, then a free first lesson.
Everything here stays free. If born haber cycle is where the marks keep going, I teach it one to one from the mark schemes. Free intro call, then a free first lesson.