Predictions for Chemistry 2014 HSC? (1 Viewer)

[photastic]

definitely there will be some mole questions.

Duhhhhhhh

 

[faisalabdul16]

rofl mate

Why should more research be enforced in the biopolymer field?

 

[faisalabdul16]

no one answered

 

[photastic]

no one answered

Because biopolymers suck tbh.

 

[faisalabdul16]

Because biopolymers suck tbh.

hahaha they're interesting.

There has been an acid spill. Which substance do you use to combat this problem and why?

 

[photastic]

hahaha they're interesting.

There has been an acid spill. Which substance do you use to combat this problem and why?

Amphiprotic or basic substances such as NaHCO3 and NaOH as this will neutralise the acid. (EG equation for HCl and NaOH neutralisation) Refer to conjugate acid and base to explain the idea of neutralising it into an end product that is neutral.

 

[faisalabdul16]

Amphiprotic or basic substances such as NaHCO3 and NaOH as this will neutralise the acid. (EG equation for HCl and NaOH neutralisation) Refer to conjugate acid and base to explain the idea of neutralising it into an end product that is neutral.

With these questions, i was advised to only talk about amphiprotic substances such as sodium hydrogen carbonate. Using NaOH could cause more problems, what if there is excess NaOH, then you have another problem that arises.
Sodium hydrogen carbonate can be used in excess.

 

[QZP]

Hahaha fixing an acid spill with a base spill

 

[photastic]

With these questions, i was advised to only talk about amphiprotic substances such as sodium hydrogen carbonate. Using NaOH could cause more problems, what if there is excess NaOH, then you have another problem that arises.
Sodium hydrogen carbonate can be used in excess.

Whoops. Thanks band 6.

 

[faisalabdul16]

Whoops. Thanks band 6.

hahah

Hahaha fixing an acid spill with a base spill

hahahah

hence why sodium hydrogen carbonate better choice.

plus in their marking criteria, they're probably looking for amphiprotic substance.

 

[photastic]

hahah




hahahah

hence why sodium hydrogen carbonate better choice.

plus in their marking criteria, they're probably looking for amphiprotic substance.

Thanks state rankers. I wouldve got zero if it popped up

 

[Futuremedstudent]

Duhhhhhhh

also balancing equations

 

[faisalabdul16]

also balancing equations

noob

Thanks state rankers. I wouldve got zero if it popped up

QZP is the state ranker.

What is the role of the salt bridge in a galvanic cell?

 

[faisalabdul16]

Radioisotopes are used in industry, medicine and chemical analysis. For ONE of these fields, relate the use of a named radioisotope to its properties.

 

[timeflies]

What is the role of the salt bridge in a galvanic cell?

Can I join in on this game?

- As oxidation occurs at the anode, electrons are lost by the electrode and cations go into solution. This results in a build-up of positive charge in the oxidation half-cell. Similarly, as reduction occurs at the cathode, cations in solution gain electrons and deposit on the cathode. This results in a build up of negative charge in the reduction half-cell.
- As the positive charge builds up in the oxidation half cell, the anion from the salt bridge (eg. NO3-) migrates towards it and neutralises the charge. Similarly, as negative charge builds up in the reduction half cell, the cation from the salt bride (eg. K+) migrates towards it to neutralise the charge.
- Thus, a salt bridge is able to keep the galvanic cell electrically neutral increasing efficiency of the cell.
- A salt bridge also facilitates the migration of ions between half-cells, thus completing the circuit.

 

[timeflies]

Radioisotopes are used in industry, medicine and chemical analysis. For ONE of these fields, relate the use of a named radioisotope to its properties.

- Technetium-99m is used in medicine for medical diagnosis and tracing.
- Tc-99m has varying oxidation states and is very reactive, allowing it to bind to many biological molecules for use inside the human body. For example, mixed with tin, Tc-99m can bind to red blood cells and trace blood flow around the body. Areas showing a large concentration of radioisotope may indicate a tumour while blood clots would appear as a break in gamma radiation.
- It is a low energy gamma emitter, allowing radiation to be easily detected outside the body without causing major damage to the body.
- It has a short half-life of 6 hours and is non-toxic meaning it does not cause damage inside the body for large amounts of time and there is minimum exposure of radiation to nearby cells.
- This allows for its relatively safe use inside the human body to help diagnose medical problems that would otherwise be harder to detect.

 

[faisalabdul16]

Can I join in on this game?

- As oxidation occurs at the anode, electrons are lost by the electrode and cations go into solution. This results in a build-up of positive charge in the oxidation half-cell. Similarly, as reduction occurs at the cathode, cations in solution gain electrons and deposit on the cathode. This results in a build up of negative charge in the reduction half-cell.
- As the positive charge builds up in the oxidation half cell, the anion from the salt bridge (eg. NO3-) migrates towards it and neutralises the charge. Similarly, as negative charge builds up in the reduction half cell, the cation from the salt bride (eg. K+) migrates towards it to neutralise the charge.
- Thus, a salt bridge is able to keep the galvanic cell electrically neutral increasing efficiency of the cell.
- A salt bridge also facilitates the migration of ions between half-cells, thus completing the circuit.

Yes the more people the better!

Ask questions after you answer one

 

[timeflies]

Yes the more people the better!

Ask questions after you answer one

Awesome! Describe the processes involved in the industrial production of ethanol from sugar cane.

 

[faisalabdul16]

Awesome! Describe the processes involved in the industrial production of ethanol from sugar cane.

Cellulose is extracted from the sugar cane. Suspension cellulose containing materials are heated moderately with concentrated sulfuric acid (4M) to break down the cellulose into glucose. The insoluble matter, particularly lignin from wood pulp is then filtered off. Impurities that are attached to the glucose are fractionally distilled and removed, and the acid is neutralized to produce a pure solution of glucose. Ethanol is then produced via fermentation. Fermentation is the process by which glucose is broken down by yeast, in the absence of air (anaerobic respiration) and at 35 degrees celsius to produce ethanol and carbon dioxide.

Outline the steps required in producing a standard solution and justify the choice of solid you use.

 

[mreditor16]

lol, thread needs to be renamed 2014 Pre-HSC Marathon Thread