Ellele Me
bacterium A
Covered with
bacterium B
Placedo
covered with
bacterium C
each pla
Clear zone
bacteria
Incubation at 37°C for 48 hours
Bacterial
growth
Result
[Adapted from 2004 HSC NSW: Section 1 - Part B Q27)
The plates were incubated at 37°C for 48 hours. The diagram of plates 1, 2 and 3
in the bottom row show the results of the investigation.
2.1 Formulate a hypothesis for this investigation.​

Straightforward questions answered in the powerpoint slidesreaction: heating the starting materials under refluxwhat does it mean to heat under reflux? why do we choose water as the reflux solvent? what are boiling chips used for? why do we put a condenser on top of the reaction? why do we add heat and let the reaction stir for 30 minutes? why do we add sulfuric acid to the reaction after it cools as opposed to when it’s still hot? separation: filtration of precipitatewhy don’t we do an aqueous and organic extraction in the separatory funnel? why do you rinse the salicylic acid on the filter with ice cold water? purification: recrystallization of salicylic acid (no hot filtration needed)what is the difference in the amount of room temperature water vs. boiling water needed to dissolve the salicylic acid (assume a 1.2 gram yield of salicylic acid)? remember, in the lab if you need x ml of boiling water to dissolve a solid, then you should add a little more (definitely no more than 1.5 times the theoretical amount) to ensure it doesn’t recrystallize prematurely.analysis: melting point of salicylic acidwhat can you conclude if the melting point of the salicylic acid you just synthesized is 152-155oc and the 1: 1 mix of your product and “synthetic” salicylic acid is 151-154oc?

Which of the following is the molecular formula for a simple sugar? a. cooh b. h2o c. oh d. c6h12o6

Is the flow of energy during vaporizing more like the flow during melting or during freezing