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Had trouble with these two problems: A liquid used in the production of perfumes, flavouring agents, emulsifying agents and disinfectants contains only carbon, hydrogen and oxygen. When it is completely oxidised in air, a 1.50g sample produces 3.00g of carbon dioxide and 1.227g of water...

Isn't it supposed to be that we 'usually' add an acid to the base? There are exceptions, but...

I see :) It's all good, except 'dilution makes diminishes non-systematic errors...' In the burette... or... everywhere? I think you oddly swapped it around in the second bit, and thought the vinegar went in the burette, and the NaOH went in the flasks, but it was really the other way around...

Isn't it bases that dissociate? Acids like ethanoic acid would go: CH3COOH(aq) + H20(l) <----> CH3COO-(aq) + H30+(aq) I think. You'd get some CH3COO- and H30+ ions in solution, and some CH3COOH... Then when you add the NaOH what happens... ? *puzzled* Help!! =S So mainly, questions are...

For instance if we had ethanoic acid (in vinegar) titrated against a NaOH standard in the burette, and the vinegar is diluted to, eg. 250ml, the volume of the volumetric flask before taking out aliquots... why is the vinegar be diluted? :confused: Using the example above, if I were to...

Some quick questions... 25.00mL of a 0.100M solution of HCl is added to 25.00mL of a 0.180M solution of NaOH. The concentration of OH-(aq) remaining in the solution, in M, is? 50.00mL of a 0.020M solution of Ba(OH)2 is added to 50.00mL of a 0.060M solution of HNO3. THe hydrogen ion...

I was thinking... what are the safety precautions of titrations, (apart from wearing lab coats and safety glasses)? I was doing a question where we had to write out the ionic equation of this reaction: CH3COOH(aq) + KOH(aq) ---> CH3COOK(aq) + 2H20(l) When I separated the ions and cancelled them...

First bit: Ah, thought so... pointless, tricking questions... Second bit: hmm, might've made a good point

:)

Just wondering what errors there are relating to titration, apart from these ones: -Accuracy in reading the meniscus -Rinsing of the glassware with wrong solution -Choice of indicator -Choice of primary standard -Scale calibration errors -Judgement of end point -Inaccuracies of measuring out...

Thanx for that ;) Does the NaOH also react with CO2? Is it unstable? Just wondering. I was thinking how the answer should be that it doesn't affect it at all. Wondered where there was any point to the question. For the last thing, I was asking, wouldn't the number of mole of Na2CO3 be...

For any graph, are dilations supposed to affect translations? When I consider it, they shouldn't, not all the time at least... eg. The simplest graph I can think of, y=(3x+1)^2 vs y=(x+1)^2... You'd think that as dilations are done first, you dilate (the 3), and the graph shouldn't move from...

Hmm... hydroscopic refers to? Never heard the term before, I dun think... -Why is solid sodium hydroxide not used as a primary standard when standard solutions of bases are required? -How would the accuracy of the standard solution be affected if the volumetric flask had been rinsed with...

Some things I would like to clear up: Does the acid ALWAYS go in the burette, even when it's not the standard solution? I've come across the expection where HCl is standardised with the base in the burette because it's safer... What are some examples of substances that should not be used as...

Okey, thnx :) :) In the write-up, there was a thing that stumped me. It asked us what other substances could have been in the tablet. They didn't seriously want us to list the ingredients did they?!

Isn't that meant to be y=lim(xgoes to -infinity) (x-2)2^(1-x) ? Multiplication, not division, and if you don't put brackets in it changes the equation... ^^

Hmmm... anybody know?

They sure are :) Without 'em, so many of the chemical processes in our body would take soo long to finish, we wouldn't really survive. heheh. Oh, and ... I realised that there are two definitions of both macro and micronutrients, that's why I got confused. The first refers to Carbs...

Ah... ok... can that be done algebraically?

This equation: f(x)= (x-2)2^(x-1) Says to state the equation of the horizontal asymptote. How do I do I do this without using a calculator? :wave: