How was chem p34

[KatnissEver]

Yeah no colour change for KI. What grade are you expecting

 

[asadalam]

An A IA, usually gt is around 27 expecting at least 30

 

[lesnar8]

did they ask to identify 2 anions or only one anion? And did they give two different blanks for anions or just one? I can't remember whether I wrote only sulfate or sulfate/sulfite. If they gave 2 blanks like they did for cations then I wrote it properly..

 

[M.Fazy]

ask me which ones.. i know correct answers for all

Hey there, can you inbox me the answers ? Thanks. ^^

 

[Amandaissocoollike]

oh my god i just realised i forgot to convert joules to KJ... i got the right value but i forgot to convert!! how many marks am i losing here??

 

[hassannouman]

Q.1) Titration

• At my centre, supervisor's titre value = 26.00 cm3
• My mean titre value (Volume of FB2 used) = 26.25 cm3

Q.2) Enthalpy change

• Temperature fall in 1st experiment = 8.0 °C
• Temperature fall in 2nd experiment = 13.0 °C
• Mean temperature fall = 10.5 °C
• Enthalpy change of solution = +14.7 kJ/mol
• 1st Experiment had greater % error because smaller mass was used.
• % error = 6.25%

Q.3) Salt Analysis

• Cation in FB4 = Manganese (II)
• Anion in FB4 = Chloride
• Suggested cations in FB5 = Magnesium or Aluminium
• Suggested anions in FB5 = Sulfate or Sulfite
• Cation in FB5 = Magnesium (II)
• Cations in FB6 = Ammonium and Iron (III)

 

[hassannouman]

oh my god i just realised i forgot to convert joules to KJ... i got the right value but i forgot to convert!! how many marks am i losing here??

Probably 1 mark only

 

[hassannouman]

ask me which ones.. i know correct answers for all

What are the correct answers?

 

[Mahamudul Hassan]

It wwas gud... Alhamdulillah...
wat was the titre volume?
pls inbox me if u are not allowed to reply here...

My titre volume was 26.3 cm^3.

 

[Abdul Hanan]

Q.1) Titration

• At my centre, supervisor's titre value = 26.00 cm3
• My mean titre value (Volume of FB2 used) = 26.25 cm3

Q.2) Enthalpy change

• Temperature fall in 1st experiment = 8.0 °C
• Temperature fall in 2nd experiment = 13.0 °C
• Mean temperature fall = 10.5 °C
• Enthalpy change of solution = +14.7 kJ/mol
• 1st Experiment had greater % error because smaller mass was used.
• % error = 6.25%

Q.3) Salt Analysis

• Cation in FB4 = Manganese (II)
• Anion in FB4 = Chloride
• Suggested cations in FB5 = Magnesium or Aluminium
• Suggested anions in FB5 = Sulfate or Sulfite
• Cation in FB5 = Magnesium (II)
• Cations in FB6 = Ammonium and Iron (III)

only thing i think is wrong here is the % error which i also got wrong.

 

[muhammadali233]

Q.1) Titration

• At my centre, supervisor's titre value = 26.00 cm3
• My mean titre value (Volume of FB2 used) = 26.25 cm3

Q.2) Enthalpy change

• Temperature fall in 1st experiment = 8.0 °C
• Temperature fall in 2nd experiment = 13.0 °C
• Mean temperature fall = 10.5 °C
• Enthalpy change of solution = +14.7 kJ/mol
• 1st Experiment had greater % error because smaller mass was used.
• % error = 6.25%

Q.3) Salt Analysis

• Cation in FB4 = Manganese (II)
• Anion in FB4 = Chloride
• Suggested cations in FB5 = Magnesium or Aluminium
• Suggested anions in FB5 = Sulfate or Sulfite
• Cation in FB5 = Magnesium (II)
• Cations in FB6 = Ammonium and Iron (III)

did you copied mine ? lol i got the same results as you except for the titre i was getting 26.5 whereas my supervisor was getting 25.8 :/ how much marks will i be losing in this ?
another thing;i used my titration results for my moles calculation (obviously) if my titre volume was incorrect will i be getting ecf? -_- how much i'll be losing in Question 1?

 

[muhammadali233]

only thing i think is wrong here is the % error which i also got wrong.

Nig i was getting the same

 

[Abdul Hanan]

did you copied mine ? lol i got the same results as you except for the titre i was getting 26.5 whereas my supervisor was getting 25.8 :/ how much marks will i be losing in this ?
another thing;i used my titration results for my moles calculation (obviously) if my titre volume was incorrect will i be getting ecf? -_- how much i'll be losing in Question 1?

3 marks as my supervisor told me. Nothing else.

Nig i was getting the same

how did you calculate?

 

[asadalam]

There would be total 5 marks for accuracy with supervisor results.3 in titration,2 in Enthalpy change one.

 

[muhammadali233]

3 marks as my supervisor told me. Nothing else.

how did you calculate?

.5/8 *100

 

[asadalam]

.5/8 *100

It would have be 1/8*100.As we take 2 readings and in every there is chance of 0.5 error so max in 2 is 1

 

[muhammadali233]

It would have be 1/8*100.As we take 2 readings and in every there is chance of 0.5 error so max in 2 is 1

cool

 

[asadalam]

Any idea on the gt?

 

[Sifat Bin Quadery]

ask me which ones.. i know correct answers for all

Wat were the ions in the last question??

 

[hassannouman]

did you copied mine ? lol i got the same results as you except for the titre i was getting 26.5 whereas my supervisor was getting 25.8 :/ how much marks will i be losing in this ?
another thing;i used my titration results for my moles calculation (obviously) if my titre volume was incorrect will i be getting ecf? -_- how much i'll be losing in Question 1?

lol not copied, it's just the same. Probably 3 to 4 marks, examiner will consider ecf so don't worry for moles calculation