I got 2 as my first go, but thought that it couldn't be right, so i did something else and got some other answer... god knows what was the right one though. On the whole, the test was ok. Industrial chemistry was a bit strange, i don't remember doing the prac that was asked but i remember reading about it so it was ok. Just be happy that it's over people... i know i am!!!!XcarvengerX said:Question 17 part b isn't it? I got pH=2 somehow.
Anyway, the test is good I think. People think it was easy but when you look at the details, it wasn't really that easy.
which i did xDhaque said:Ammonium chloride is correct-however in the ionisation equation u have to show its an equilibrium
You get pH 2 if you worked out the pH straight after figuring out the HCl that remained in excess, which was about 0.0098 mol. However, you needed concentration, and that value is just 0.0098 mol / 70mL. You had to convert that to mol/L, which came to about 0.14, I think. That gave you pH ~0.85.Lauren_Melrose said:I got 2 as my first go, but thought that it couldn't be right, so i did something else and got some other answer... god knows what was the right one though. On the whole, the test was ok. Industrial chemistry was a bit strange, i don't remember doing the prac that was asked but i remember reading about it so it was ok. Just be happy that it's over people... i know i am!!!!
I am relieved someone wrote the same as me. Cause the left side the metals are basic oxides and the right side are acidic. However it can be seen that the conjuagate base of a strong acid and the conjugate acid of a weak base or something like that was used, however that explanation couldn't be used as they only allowed the one with an equation which u had to write with fucking water. MY teacher showed me the night before the exam how to do it!!!! and I forgot totally and now remember after the exam!!!!! goddamit!angmor said:i did ammonium chloride for that...i dont know if its an 'experimental salt' if you know what i mean, like if its acutally obtainable in a school laboratory,,,,so might get that wrong
WouldbeDoctor said:I am relieved someone wrote the same as me. Cause the left side the metals are basic oxides and the right side are acidic. However it can be seen that the conjuagate base of a strong acid and the conjugate acid of a weak base or something like that was used, however that explanation couldn't be used as they only allowed the one with an equation which u had to write with fucking water. MY teacher showed me the night before the exam how to do it!!!! and I forgot totally and now remember after the exam!!!!! goddamit!
Trebla said:It was alright, but at the same time it was an annoying exam.
The multiple choice questions were quite tricky (e.g. For the Glucose question, did you remember it was a condensation polymer so you had to subtract masses of 4 water molecules? I would imagine heaps of people fell for the trick).
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i didnt!
yay!
my teacher seemed to think i was better at chem than in physics. im expecting about 75+ raw in physics and about 50 in chem. haha i told him that at my formal last night. he didnt seem too impressed.earthnfire said:i loveeedd the multiple choices...pretty sure i'll get 14 outa 15...the rest of the exam was good....i'm hoping for a raw mark of 85+....chem's one of my best subjects