D
d00d
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whos doing it? are there any tips? the method is way harder this time, the filtering takes aggggges...
y is it harder? u gotta filter?? it's not the same???Originally posted by d00d
whos doing it? are there any tips? the method is way harder this time, the filtering takes aggggges...
to filter or not to filter...Originally posted by d00d
spicegirl: how can u not filter? u need to filter out the Ba2SO4 so all u've got left is the acid, and then u make it up to the 100mL mark.
iambored: its a lot longer and harder this time, 3 hrs of it. u gotta make up the primary standard urself and in the second titration they deliberately contaminated it with Ba2SO4 which is why u have to filter it.
to get gold u need a result within 1% of the correct answer, i wonder how many ppl got it last year?
oh wowOriginally posted by d00d
spicegirl: how can u not filter? u need to filter out the Ba2SO4 so all u've got left is the acid, and then u make it up to the 100mL mark.
iambored: its a lot longer and harder this time, 3 hrs of it. u gotta make up the primary standard urself and in the second titration they deliberately contaminated it with Ba2SO4 which is why u have to filter it.
to get gold u need a result within 1% of the correct answer, i wonder how many ppl got it last year?
I think there was more than 5.Originally posted by sarah_#1_eel
Was it Held at Bondi?? I went to one and l got the second lowest out of about 5 schools.
Originally posted by d00d
whos doing it? are there any tips? the method is way harder this time, the filtering takes aggggges...
Originally posted by d00d
to get gold u need a result within 1% of the correct answer, i wonder how many ppl got it last year?
a) i did the national titration competition last yearOriginally posted by snow bum
Surely trying to filter out BaSO4 would be like banging your head against a brick wall?
spice girl is rightOriginally posted by spice girl
to filter or not to filter...
you have to consider which would cause you more error: the volume displacement caused by the BaSO4 (which to my recollection is waaay less than 1ml). Considering that the volumetric is at least 100mL (i can't remember if 100 or 250), that's less than 1% error. Remember that adding a drop too many (to make up the mark) may give you more volume error than the BaSO4 volume.
On the contrary, if you filter, you have to wash the damn filter (cos the KHP will get soaked in the paper). This means you have to use less water to dissolve ALL the KHP (which is hard to tell when all the KHP is dissolved, since both KHP and BaSO4 is white). In addition, filtering may mean splashing if you're not careful. Also, you have to be careful when you wash the filter that you don't accidentally add more water than you need.
IMHO, filtering is being fussy. We had no problems getting more golds than non-golds. Also i managed to finish in 90min
i likeOriginally posted by jm1234567890
lol, i didn't even make it past the region... too boring, i'm too impatient