"h Wear goggles, apron and gloves to be safe in case of spillage or accidental contact with clothing.
"h Upon contact with solution it is advisable to wash hands or affected body part immediately. Be careful as it burns.
"h If breakage of tubes/beaker occurs, clean up immediately.
"h In order not to confuse test tubes containing water and hydrogen peroxide, label each of them clearly
"h Remember to wash hands after handling yeast suspension
To ensure that a fair test is carried out the following must be observed
"h Make sure fixed variables are not altered
"h Make sure that when the volume of yeast and water is changed and then added to hydrogen peroxide the total volume is 8 cm3.
"h Make sure the volume of hydrogen peroxide in all the experiments is kept constant at 3 cm3
"h Ensure the clamp is firmly in place so there are mishaps and no interruptions
"h Carry out experiment more than once and then find an average this should eliminate anomalies
"h Mix the reagents and start the clock at the same time, so that the correct value will be got.
"h Make sure air bubbles aren't formed before the reaction begins by using the bung
"h Try as much as possible to avoid parallax error.
FINAL CHOICE OF EQUIPMENT
The set up of my apparatus will be similar to my preliminary experiment, just a few changes have been made and a few things added:
"h Clamp (x1) (indicated by arrow)
"h Metal retort stand (x1)
"h Electronic timer (recording to 1 sec intervals) (x1)
"h Beaker (500 cm3) (x1)
"h Micro test tube to fit into side-arm boiling tube
"h Large side-arm boiling tube and bung fitted with delivery tube to fit (x5)
"h Graduated measuring cylinder...