Predictions for Chemistry 2014 HSC? (1 Viewer)

[Queenroot]

k

Seen

 

[faisalabdul16]

Calculation questions anyone??

 

[SuchSmallHands]

I think we'll get a good calculation question this year.

Try this one:

The solubility of highly soluble, thermally unstable salts such as ammonium chloride may be determined by back titration.

In one experiment a 5.00 mL saturated solution of ammonium chloride, NH4Cl, at 20oC,
was diluted with distilled water to 250.0 mL in a standard flask.

A 20.0 mL aliquot of this solution was added to 10.0 mL of 0.400 M NaOH solution.
The solution was heated to drive off the ammonia formed by this reaction.

When the flask had cooled, the excess hydroxide ions were neutralised by 14.7 mL of 0.125 M HCl solution. The molar mass of ammonium chloride is 53.5 g/mol.

(i) Write an equation for the neutralisation reaction.
(ii) Determine the amount, in mole, of NaOH that was originally added to the ammonium chloride solution.
(iii) Determine the amount, in mole, of ammonium chloride in the 20.0 mL aliquot.
(iv) Calculate the amount, in mole, of ammonium chloride in 5.00 mL of the saturated solution.
(v) Calculate the solubility, in g/L, of ammonium chloride in water at 20oC.

7 marker, 1 + 1 + 2 + 1 + 2

This was from the 2012 VCE Chemistry Paper for those interested.

i. NH4Cl + NaOH ---> H20 + NaCl + NH3
ii. 0.004 mol
iii. 0.0021625 mol
iv. 0.02703125 mol
v. 289.234375 g/L

I think that's what I've written anyway, my working out is an absolute mess and I'm not quite sure which numbers were actually the answers to each question.

 

[SuchSmallHands]

^ Has anyone one else done this

 

[Jim Moriarty]

i. NH4Cl + NaOH ---> H20 + NaCl + NH3
ii. 0.004 mol
iii. 0.0021625 mol
iv. 0.02703125 mol
v. 289.234375 g/L

I think that's what I've written anyway, my working out is an absolute mess and I'm not quite sure which numbers were actually the answers to each question.

Marks are in sequential order, i -> 1 mark, ii -> 1 mark ,etc..

I believe i) is simply HCl + NaOH --> NaCl + H2O
Other than that, the rest are correct - just cut back on the number of significant figures .

 

[SuchSmallHands]

Marks are in sequential order, i -> 1 mark, ii -> 1 mark ,etc..

I believe i) is simply HCl + NaOH --> NaCl + H2O
Other than that, the rest are correct - just cut back on the number of significant figures .

Woo, thanks

 

[faisalabdul16]

Haber is a criminal.

To what extent do you agree with this statement. :]

 

[enigma_1]

Haber is a criminal.

To what extent do you agree with this statement. :]

Who actually reads that far into "chemistry"..

oh yeah that's right fsFawfershgabdul16

 

[faisalabdul16]

Who actually reads that far into "chemistry"..

oh yeah that's right fsFawfershgabdul16

hahahaha my teacher

-_________- tried to hide it from me

 

[enigma_1]

hahahaha my teacher

-_________- tried to hide it from me

Lel

inb4thenextchemsyllabusincludessomethingaboutHaberbeingacriminal

chem is so fkd lyk dat

 

[Queenroot]

Lel

inb4thenextchemsyllabusincludessomethingaboutHaberbeingacriminal

chem is so fkd lyk dat

Hammond also told us about it

 

[faisalabdul16]

Lel

inb4thenextchemsyllabusincludessomethingaboutHaberbeingacriminal

chem is so fkd lyk dat

hahahaha my teachers reason for him not being a criminal:

He was a scientist and scientists do not involve themselves in politics or anything like such, thereby he is not a criminal but a man who solved multiple problems that had not begun to even affect the world yet.

 

[enigma_1]

Hammond also told us about it

LOLLL all of them did.

lol at school we get taught everything that's not in the syllabus >.<

 

[enigma_1]

hahahaha my teachers reason for him not being a criminal:

He was a scientist and scientists do not involve themselves in politics or anything like such, thereby he is not a criminal but a man who solved multiple problems that had not begun to even affect the world yet.

lol

 

[Hi there444]

hahahaha my teachers reason for him not being a criminal:

He was a scientist and scientists do not involve themselves in politics or anything like such, thereby he is not a criminal but a man who solved multiple problems that had not begun to even affect the world yet.

I am a criminal for not doing anything to affect the world.

 

[SuchSmallHands]

Haber is a criminal.

To what extent do you agree with this statement. :]

If he is a criminal, I think history has more than persecuted him for any transgressions. To know that a significant portion of your life's work involved the establishment of a chemical corporation that was to later attempt to entirely annihilate your own race wouldn't be enjoyable.

 

[zhertec]

I'm actually really curious to how old "Futuremedstudent" is. Some threads state like he's in year 10 or something...so does anyone really know like how old he is?

 

[enigma_1]

I'm actually really curious to how old "Futuremedstudent" is. Some threads state like he's in year 10 or something...so does anyone really know like how old he is?

He?


Hahahahhah

 

[zhertec]

Futuremedstudent is female? O_O *mind blown*

 

[SuchSmallHands]

Assess the use of ethene as a raw material (5 marks)

Someone answer this? (and I also thought FMS was not doing their HSC this year)