Required Practical 5: Rates of Reaction 1

Question 1

Define hypothesis.

Answer 1

proposal that could explain a fact or observation

Question 2

Step 1?

Answer 2

use measuring cylinder to put 10cm^3 of sodium thiosulfate solution into conical flask

Question 3

Step 2?

Answer 3

place conical flask on printed black cross

Question 4

Step 3?

Answer 4

add 10cm^3 hydrochloric acid into conical flask, swirl & start stopwatch

Question 5

Step 4?

Answer 5

stop timer & record time when solution has become cloudy & you can no longer see X

Question 6

Step 5?

Answer 6

repeat steps 1-5 with diff. concs. of sodium thiosulfate & calc. mean of all values (excpt anomalies)

Question 7

What makes a measurement reproducible?

Answer 7

can be repeated by diff. person or using diff. tchnq or equipment & still get same result

Question 8

Whatv is the problem with the disappearing cross experiment?

Answer 8

diff. ppl have diff. eyesights

Question 9

In this experiment, what are you investigating?