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No, you can't use fractional distillation to determine ethanol content because water and ethanol form an azeotrope and the vapour will always be a mixture of both. An indirect method of determining ethanol content can be calculated by the mass loss from CO2 in the reaction. As for yeast...

A hydrometer to determine density will also work.

This process can have low yield so it won't give you a good estimate of ethanol content. There are analytical techniques that can determine ethanol content to ~1% like GC, HPLC, or even NMR.

Yes, Br2 is volatile. The material you're testing may also be volatile. In chemistry, you should aim to do everything in a fume hood.

The question is written badly because it's 1,1,1-trichloro-2,2,2-trifluoroethane and CFC-113a. However, you can still easily do the question as is.

I'm not sure exactly what the HSC requires. However, bond breaking in most reactions involves either removing electrons from a bonding orbital or adding electrons to the antibonding orbitals. For homolytic cleavage, the energy increase (e.g. light breaking a bond), you'd end up with it going...

There is less orbital overlap in pi bonds than sigma bonds. Essentially, the electron density in sigma is directly between the two atoms so it's better at keeping the two atoms together.

By substitution, I assume halogenation reactions. Yes, you can do it with fluorine, which is much more reactive and basically uncontrollable/explosive (this is why you don't learn about it). Iodine is less reactive because when you get iodine radicals, the hydrogen atom abstraction is slow...

Err, removing an electron would be oxidising it lol. Bond breaking can be homolytic (one electron goes to each atom) or heterolytic (both electrons in the bond go to one atom).

Being flat is good (e.g. benzene) and avoid big bulky groups (e.g. t-Bu).

Cyclohexene becomes 1,2-dibromocyclohexane. If it's bromine water (and not just liquid bromine), the water can compete in the second step, so you might get a mixture with hydroxylation in the second step. Cyclohexane slowly becomes bromocyclohexane. It's light-activated by breaking the Br-Br...

I'd argue that it's technically wrong to say UV catalysed because the UV is consumed in the reaction. It's more accurate to describe it as UV activated/mediated.

Not exactly sure I'd agree with a broad statement like that. You can have intramolecular hydrogen bonds, for example, which can disrupt/compete with the formation of intermolecular hydrogen bonds.

Question is too vague.

I kinda hate how it's an "evaluate" question. In reality, it should just be: "the experiment has no repetitions, so it is not reliable". Anyway, a couple of points to consider: Probably better to filter with a Buchner funnel with filter paper (sintered glass is honestly pretty bad since a lot...

Well, if it's wet, then you're measuring the mass of two things - your analyte and water. It's basically equivalent to not taring your balance.

Ketones are slightly more polar than aldehydes. Essentially, alkyl chains are mildly electron-donating, so it puts a more negative charge on the oxygen atom.

B

In general, I just bullet point a few keywords that I want to talk about. So it's like, 5 to 10 words.

Yeah, they made an error but ended up not mattering because Pb(II) and carbonate are in a 1:1 ratio.