Predictions for Chemistry 2014 HSC? (2 Viewers)

[enigma_1]

Wait what is an analytical chemist? It sounds so boring whatever it is

 

[iStudent]

 

[SuchSmallHands]

Wait what is an analytical chemist? It sounds so boring whatever it is

They just test things, like run AAS/Fluorescence Spec/X-ray crystallography all the time. It really does sound boring as hell.

 

[iStudent]

Trusty Dusty is up to his old tricks again – poisoning his mother’s pot plants with aqueous acid-laced
fertiliser. Realising that the acid (HX – molar mass 27.03 g mol–1) is potentially incredibly dangerous
to humans (quite volatile) he realises that he needs the free anion (X–) concentration in his fertiliser
to be 0.00340 mol L–1. First, he does a quick test. If, when he adds the equivalent of 0.560 g of HX to
50.0 mL of water, the pH is measured to be 3.67, how much HX should he add to 4.00 L in order to
prepare his fatal fertiliser?

edit: dw about this q

 

[enigma_1]

They just test things, like run AAS/Fluorescence Spec/X-ray crystallography all the time. It really does sound boring as hell.

Ohhh ok ahahha i know right

 

[GOsie]

Describe how atomic absorption spectroscopy is used to detect concentrations of metal ions in solution. (4 marks)

 

[Hi there444]

I'm not sure, however what they were looking for was stuff like Haber and Bosch

Hahaha half the stuff was on haber

_/_/_

 

[faisalabdul16]

Hahaha half the stuff was on haber

_/_/_

As in collaboration between Haber and Bosch.

Haber produced ammonia
Bosch produced it on an industrial scale etc etc

 

[enigma_1]

As in collaboration between Haber and Bosch.

Haber produced ammonia
Bosch produced it on an industrial scale etc etc

Omg who is this bosch?!

 

[Hi there444]

As in collaboration between Haber and Bosch.

Haber produced ammonia
Bosch produced it on an industrial scale etc etc

Omg who is this bosch?!

^^^. Bosch is not syllabus

_/_/_

 

[enigma_1]

^^^

_/_/_

But like how do we know we're meant to talk about bosh in the question? Wot even~

 

[Hi there444]

But like how do we know we're meant to talk about bosh in the question? Wot even~

Well thanks fais for telling us

_/_/_

 

[SuchSmallHands]

Describe how atomic absorption spectroscopy is used to detect concentrations of metal ions in solution. (4 marks)

- Sample of the solution is aspirated into the flame within the Atomic Absorption Spectrometer.
- A sample of the substance being tested for is excited in a hallow cathode lamp to emit a specific wavelength that will be absorbed by the ion if it is present in the solution.
- The light which passes through the sample passes through a monochromator to isolate the wavelength of light that will be absorbed by the ion being tested for, which is then detected by a detector (uh, should probably phrase that a bit better)
- Absorption is compared to a calibration curve to determine ion concentration

 

[Hi there444]

- Sample of the solution is aspirated into the flame within the Atomic Absorption Spectrometer.
- A sample of the substance being tested for is excited in a hallow cathode lamp to emit a specific wavelength that will be absorbed by the ion if it is present in the solution. Can detect very small conc in ppm
- The light which passes through the atomized sample from nebulizer passes through a monochromator to isolate the wavelength of light that will be absorbed by the ion being tested for (diffraction grating), which is then detected by a detector (uh, should probably phrase that a bit better)
- Absorption is compared to a calibration curve from standard solutions to determine ion concentration. Absorbance is prop to conc.

I changed it bit to get all marks

_/_/_

 

[SuchSmallHands]

Sample of the solution is aspirated into the flame within the Atomic Absorption Spectrometer.
- A sample of the substance being tested for is excited in a hallow cathode lamp to emit a specific wavelength that will be absorbed by the ion if it is present in the solution. Can detect very small conc in ppm
- The light which passes through the atomized sample from nebulizer passes through a monochromator to isolate the wavelength of light that will be absorbed by the ion being tested for (diffraction grating), which is then detected by a detector (uh, should probably phrase that a bit better)
- Absorption is compared to a calibration curve from standard solutions to determine ion concentration. Absorbance is prop to conc.

Can't we detect to ppb now?
Edit: just saw the diffraction grating part, the diffraction grating is in the monochromator (or not, prisms can also be used).

 

[faisalabdul16]

C/Karl Bosch is the guy who developed the necessary machinery and equipment to produce ammonia on a large scale

 

[Hi there444]

Sample of the solution is aspirated into the flame within the Atomic Absorption Spectrometer.
- A sample of the substance being tested for is excited in a hallow cathode lamp to emit a specific wavelength that will be absorbed by the ion if it is present in the solution. Can detect very small conc in ppm
- The light which passes through the atomized sample from nebulizer passes through a monochromator to isolate the wavelength of light that will be absorbed by the ion being tested for (diffraction grating), which is then detected by a detector (uh, should probably phrase that a bit better)
- Absorption is compared to a calibration curve from standard solutions to determine ion concentration. Absorbance is prop to conc.

Can't we detect to ppb now?
Edit: just saw the diffraction grating part, the diffraction grating is in the monochromator (or not, prisms can also be used).

If thats all you saw. You havent seen much changes at all.

 

[SuchSmallHands]

Looks to me like they have increased the amount of all of the gasses. Then, the first and third lines (top from bottom), decrease in concentration perhaps because they were both on the same side of the equation and that side had a higher number of moles, so LCP dictates that the equilibrium should shift to favour the other side, which is corroborated by the fact that the middle line increases in concentration.

Any other opinions on the interpretation of that graph?

 

[enigma_1]

C/Karl Bosch is the guy who developed the necessary machinery and equipment to produce ammonia on a large scale

Thanks. So that's enough ifo we need to know about him right? We can bs the rest?

 

[SuchSmallHands]

If thats all you saw. You havent seen much changes at all.

It's a little hard because you didn't bold the changes. I saw the ppm thing, the diffraction grating and 'absorbance proportional to concentration' (I agree I needed to put in the last thing, I get in shit all the time for taking things as assumed knowledge where I shouldn't)