Edexcel Chemistry Unit 4 Woes

June retakes for me lol.

Reply 42

low concentration of ethanoic acid

YES

what did people get for the pH of the fizzy drinks can, i put that when opened pH increased ?

Reply 43

increse in ph as when co1 escapes eqm shifts to the left hand side???

Reply 44

I said Ph increases as equilibrium shifts to the left, so less [H+] yield, making the acidity drop.

Reply 45

lostinspace

increse in ph as when co1 escapes eqm shifts to the left hand side???

yeah thats what i put, at first i was clueless, dont know why, seems an easy question ,but i realised if you're drinking a can of coke after a while it'll lose its fizz,which to me says increase in pH, and so just went from there

Reply 46

yepp, was methyl orange not suitable as its ph was LOWER then phenol

Reply 47

what did you put for the very last question
reaction of NaCl + water and PCl3 + water, asked for pH of resultant solutions

Reply 48

i loved the final question, 4 EASY EQUATIONS and the standard sn/pb love story!

Reply 49

hh123

omg i didnt knw the definition for dilute either!!

Reply 50

lostinspace

yepp, was methyl orange not suitable as its ph was LOWER then phenol

methyl orange pH range is 3.2 to 4.5 and the equivalence point was been 6.4 and 10.0 so was unsuitable, colour change would be red to yellow, or for phenol colorless to pink

Reply 51

nacl + h20 - na aq + cl aq so ph is 7

pcl3 + h20 = h3po3 + 3hcl so ph is anything less then 2

Reply 52

i dnt think it was about colour change i think it was the fact tht it dsnt lie on th verticle reigon of the graph

Reply 53

lostinspace

nacl + h20 - na aq + cl aq so ph is 7

pcl3 + h20 = h3po3 + 3hcl so ph is anything less then 2

damn, i got the products wrong for first reaction, silly mistake i put hcl and naoh, but still came out with ph 7
2nd one i put pH 2 so hopefully will get the marks

Reply 54

lostinspace

i dnt think it was about colour change i think it was the fact tht it dsnt lie on th verticle reigon of the graph

it said in the question you had to mention what the colour changes were for the indicators

Reply 55

remember h3po3 is a weak acid so if you put the value as 1 its wrong.

Reply 56

Cyrus The Great

remember h3po3 is a weak acid so if you put the value as 1 its wrong.

oh YES, that was my logic for putting 2 :biggrin:

Reply 57

kane28

it said in the question you had to mention what the colour changes were for the indicators

i think it said explain the colour changes as it "why do they change colour in the vertical section?"

Reply 58