.

[Martoman]

For argument's sake, an element (sufficiently close to an oxidation number of 3 or 3.5) could have an oxidation number of it wouldn't matter because it doesn't mean anything.

[fady_22]

Maltose is a dissacharide like sucrose. Sucrose is shown in the data book. Counting the
hydroxyl groups gives 8 and there are 3 ether groups counting the two in the rings themselves.

I thought only one ether :S??

Maltose is a disaccharide with two glucose molecules.
Each glucose molecule contains one ether group in the ring itself, and the link between the two glucose molecules is also an ether. In total, 3 ether groups.

[m@tty]

It's individual bonds that absorb. Go look at Mao's post...

**

Isn't that the lazy man's structural formula? I always thought that structural required all CH bonds to be expanded... In fact all bonds except OH..

But I'm not sure...

[kyzoo]

Structural formula is with all the bonds shown

Semi-structural formula is any shortcut method, such as CH3CH2OH.

[Mao]

Basic questions, but:
With IR spec, is it the bonds or the entire molecules absorbing the infra-red radiation that cause it to vibrate, stretch etc.?

****

It's individual bonds that absorb.

**

Incorrect. Both absorption occur (bonds and molecule). The molecular absorption occur at lower wavenumbers (fingerprint region), where combination of bonds/structures absorb energy. This is why every molecule have different fingerprint regions.

[kakar0t]

10. A - plot area under peak against concentration
9. not sure

[vexx]

Q4.
The equation given is a reduction, so the other has to be an oxidation which is an equation wrote with the 'e' on the right side, from this you can already tell it has to be Fe2+ ---> Fe3+ + e- or else if it were fe3+ it would be reducing.
after that balance the equations, find n(cr2o7 2-), using ratio get mole of iron, then divide the mass given of the salt by the mole, and take away the molar mass of fe, and theres your mass of the other elements.

[Martoman]

Yeah but its a case of trial and error no?

Like you get the mass of Fe then you subtract it from the mass of whole thing.

Then you need to find empirical formulas that match.

The only one that does is D.