Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
23 Cards in this Set
- Front
- Back
|
in potassium permanganate titration's what kind of substances are found out about? |
those which donate electrons - reducing agents iron fe2+ ethanedioate ion c2o42- |
|
|
how does potassium permanganate act? show in equation? |
oxidising agent MnO4- + 8H+ 5R >Mn2+ + 4H2O |
|
|
equations of using iron (II)? |
Fe2+ > Fe3+ + e 5Fe2+ + MnO4- + 8H+ > 5Fe3+ + Mn2+ + 4H2O |
|
|
how many moles of iron(II) react with permanganate? |
1 iron to 1/5 permanganate |
|
|
equations for ethanedioate ions? |
C2O42- > 2CO2 + 2e 5CrO42- + 2MnO4- +16H+ > 10CO2 + 2Mn2+ + 8H2O |
|
|
how many moles of ethanedioate react with how many moles of permanganate? |
5 ethanedioate with 2 permanganate |
|
|
what difference is there in ethanedioate titration's? |
they are at 80 degrees |
|
|
what observation is shown for the end point in permanganate titration's? |
purple to pink |
|
|
adv of using potassium permanganate? |
-no indicator -oxidises a range of chemicals |
|
|
dis of usingpotassium permanganate? |
-low solubility low conc cannot be made - not a primary standard must be standardised with iron (II) ammonium sulfate - meniscus is not clear |
|
|
what are iodinge thiosulfate titrations used for? |
find out about oxidising agents Cu 2+ and iodate IO3- |
|
|
procedure for iodine thiosulfate titrations? |
1) add potassium iodide solution to oxidising agent, idodide ions are oxidised to iodine and solutions turns brown 2) titrate the mixture with sodium thiosulfate when straw colour add starch indicator when>black/blue add more when goes colourless stop |
|
|
what indicator is used in iodine thiosulfate titrations when is it added? |
starch when the solution goes straw colour |
|
|
write equation for the reaction between iodine and thiosulfate? |
I2 + 2S2O32- > 2I- +S4O52- |
|
|
what is sodium thiosulfate standardised with? |
potassium iodate |
|
|
what observation is made when potassium iodide is added to copper(II) ions in solution? which is? |
a coffee coloured ppt
a white ppt CuI in brown solution iodine |
|
|
what colour is copper(I) iodide and iodine? |
white ppt and brown solution |
|
|
equation of iodine thiosulfate with copper (II) ions? |
2Cu2+(aq) + 4I-(aq) > 2CuI(s) + I2(aq) |
|
|
equations of iodine with thiosulfate? |
I2 + 2S2O32- > 2I- + S4O62- |
|
|
ratio iodine to sodium thiosulfate? |
1:1 |
|
|
equation for reaction between acidified potassium iodate and iodide ions? |
IO3- + 6H+ +5I- > 3I2 +3H2O |
|
|
iodine reaction with thiosulfate? |
I2+ 2S2O32- > 2I- + S4O62- |
|
|
ratio of iodine to thiosulfate ions in reaction? |
1:6 |
