Question - State one large-scale use of sulphuric acid.
Student's answer - "Soap".
Yes, I wash my face in sulphuric acid every day. That's why my skin is so red and dry. But it's great for removing grease and oils!
I am currently quite annoyed with this student, because she's been giving me 3 or 4 past papers per week, each of which is so appallingly rushed that it gives no insight as to her ability or the grade she'll achieve in the actual exam. When a 60 mark paper loses 10 marks through careless mistakes and another 10 through vague wording (when I'm sure she understands the concepts really), that's not going to get more than a C unless the grade boundaries are ridiculously low due to Extreme Hardness. An exam of one hour should be attempted in one hour, and if she finishes in 35 minutes then the remaining time should be used for checking. Argh!
My latest blitz has been on the students' habit of handing in exam papers where they've failed to write anything on some questions. In the past few days, I've marked papers with anything from 3 to 20 of the marks left completely blank. Wasting 20 of 75 marks really does reduce your maximum possible grade - to get a B, you'd need to get 100% of what you did answer correct. Also, if you leave a question completely blank, then you will, of course, obtain zero marks for it. But if you write down whatever you remember that's related to the question, you stand a chance of scoring 1 or 2 of the marks. This applies doubly when it comes to calculations. The calculations are always structured to give the marks step-by-step, so even if all you can do is calculate the molar mass of the compounds, or work out the number of moles of the first compound, that will give you 1 or 2 marks.
This advice doesn't work so well if you're sitting an exam where they take off marks for incorrect answers, but here, in the GCSE and A-level exams, you only get marks deducted if something you write is so blindingly, appallingly wrong that it contradicts the rest of your answer. For example, if you are writing about why metals conduct electricity then suddenly decide they have covalent bonding. This type of bonding contradicts what you've written about electrons and positive ions, so you'd lose all the marks on that part of the question for it.
I am also annoyed with having to tutor kids who are only sitting in-school exams rather than public exams. They just don't take the exams seriously, and will sit and argue with me that they've never learned topics even though they're on the syllabus for their age group. When I have a child in the 10th grade at an international school argue with me that he's never learned about digestive system enzymes, I laugh a lot because it's on his school's syllabus for 8th grade. Hmmm. As for the kidney, his textbook devotes a whole chapter to the nephron and ADH, and he is supposed to have covered everything in the textbook. He thinks I'm going to teach him International Baccalaureate Chemistry. I'm totally not - the IB Higher Level is ridiculously hard, and the options chosen by his school contain vast quantities of 1st and even 2nd year university chemistry (organic reaction mechanisms From Hell). It requires a lot of hard work and maturity, and I don't think he can manage either.