Mix equal volumes of A and B by pouring back and forth into beakers three times. The reaction starts on the lst pour and ENDs when the solution turns black….therefore the name CLOCK REACTION…it tells you how long the reaction takes from start to finish!
Know what do you expect to happen IF the two solutions A and B in the clock reaction dont have any starch in them? 1. Will a reaction still happen? 2. Will the result be black? 3. What will the result look like?
Solutions for the iodine clock reaction: A. 4.3 g KIO 3 per liter B. 0.2 g Na 2 S 2 O 3, 4 g soluble starch and 5 ml concentrated sulfuric acid. You can slow the reaction down by diluting A and speed it up by adding more sulfuric acid to B. You can use cornstarch, put 1 tsp in 200 ml water and heat to boil in microwave….let cool and add to B. You can use a big pinch of A, small pinch of B throw in a little sulfuric acid in B and some starch. Then adjust to suit you….
The Reaction 123 4 Mix Any HSO 4 - left? yes no 1. IO 3 - + 3HS0 3 - I - +3SO 4 -2 + 3H + 2. 5 I - + 6H + +IO 3 - 3 I 2 (aq) + 3H 2 0 3. I 2 +HSO 3 - + H 2 O 2I - + SO 4 -2 + 3 H + 4. I 2 + starch == blue solution I 2 solution appears yellowish without starch. click