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IAL jan 2017 unit one chemistry

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Do you guys think the grade boundaries are gonna be low? Whats your expectations? Im so worried.
Original post by Igcse1student
What had the highest mass economy??
In mcq

I selected the polymerisation of propene to poly(propene)..
Not sure that's right though..
Original post by edexcelstudent
I selected the polymerisation of propene to poly(propene)..
Not sure that's right though..


I wrote reforming but it sounds wrong
Original post by edexcelstudent
I selected the polymerisation of propene to poly(propene)..
Not sure that's right though..


polymerization has 100 percent atom economy so you're correct
Original post by edexcelstudent
I selected the polymerisation of propene to poly(propene)..
Not sure that's right though..


that is right
Original post by Helper OF ALL
233.56... sth


Got 0.23
Idk how I feel about this exam, really hoping for low ums
Original post by ali_a200
Got 0.23


you probably got the first part incorrect. the first part was 1818 moles because the fuel was in kilograms and you have to multiply it by 1000
What other questions were there, I can barely remember. Im really hoping for low grade boundaries.

Also there was no Born Haber cycles or the free radical mechanisms, I was really bummed out cause I liked those kind of questions.
Original post by LaylaM99
What other questions were there, I can barely remember. Im really hoping for low grade boundaries.

Also there was no Born Haber cycles or the free radical mechanisms, I was really bummed out cause I liked those kind of questions.


Umm, if I remember correctly, there was these 3 questions about propane:
1. They asked for the DeltaH Atomization of propane. I think the answer was: 3998 KJ/mol.
2. They asked for the bond enthalpy of the C-C bond. My answer was: 262.6 KJ/mol(I'm not sure about this one so please correct me if I'm wrong.
Finally,
3. They asked why are values are different from those of the data booklet. My answer was because the experiment might have not been conducted at 1 atm(1.01x 10^5 pascal) as they only mentioned temperature(298K).

Another question I remember is the bromine water one. They asked for "BEFORE SHAKING" and "AFTER SHAKING". I came up with 2 answers but I couldn't get the 3rd one =/

Hope I was able to help :smile:
[QUOTE="AlchemistYazan;69507508"]Umm, if I remember correctly, there was these 3 questions about propane:
1. They asked for the DeltaH Atomization of propane. I think the answer was: 3998 KJ/mol.
2. They asked for the bond enthalpy of the C-C bond. My answer was: 262.6 KJ/mol(I'm not sure about this one so please correct me if I'm wrong.
Finally,
3. They asked why are values are different from those of the data booklet. My answer was because the experiment might have not been conducted at 1 atm(1.01x 10^5 pascal) as they only mentioned temperature(298K).

Another question I remember is the bromine water one. They asked for "BEFORE SHAKING" and "AFTER SHAKING". I came up with 2 answers but I couldn't get the 3rd one =/

Hope I was able to help :smile:[/QUOTE
A whole mark scheme please
Original post by AlchemistYazan
Umm, if I remember correctly, there was these 3 questions about propane:
1. They asked for the DeltaH Atomization of propane. I think the answer was: 3998 KJ/mol.
2. They asked for the bond enthalpy of the C-C bond. My answer was: 262.6 KJ/mol(I'm not sure about this one so please correct me if I'm wrong.
Finally,
3. They asked why are values are different from those of the data booklet. My answer was because the experiment might have not been conducted at 1 atm(1.01x 10^5 pascal) as they only mentioned temperature(298K).

Another question I remember is the bromine water one. They asked for "BEFORE SHAKING" and "AFTER SHAKING". I came up with 2 answers but I couldn't get the 3rd one =/

Hope I was able to help :smile:

Oh yeah! I think I got the same answers as you for the Propane question. What did you put down for bromine water one ? I put that it goes colourless.
[QUOTE="Gonzalovilanova;69507558"]
Original post by AlchemistYazan
Umm, if I remember correctly, there was these 3 questions about propane:
1. They asked for the DeltaH Atomization of propane. I think the answer was: 3998 KJ/mol.
2. They asked for the bond enthalpy of the C-C bond. My answer was: 262.6 KJ/mol(I'm not sure about this one so please correct me if I'm wrong.
Finally,
3. They asked why are values are different from those of the data booklet. My answer was because the experiment might have not been conducted at 1 atm(1.01x 10^5 pascal) as they only mentioned temperature(298K).

Another question I remember is the bromine water one. They asked for "BEFORE SHAKING" and "AFTER SHAKING". I came up with 2 answers but I couldn't get the 3rd one =/

Hope I was able to help :smile:[/QUOTE
A whole mark scheme please


I don't have the paper and I forgot most of the questions haha. Still, I'll try to remember some more for you :smile:.

What are 2 things commonly shared in a homologous series:
1. Functional group
2. General formula

Molar mass of ZnSO4.7H2O: 191.5 g/mol

Number of moles of sulfuric acid: 0.02 moles

Percentage yield of hydrated ZnSO4: 48%

How to prepare Pure, dry hydrated ZnSO4:
You have to try to squeeze in filtration and crystallization/evaporation in 4 marks.

Ionic equation:
Zn(s) + 2H^+ -----------> Zn^2+ and H2(g)

Observations:
1. Solid disspears
2. Bubbles of gas

Number of protons, neutrons, and electrons of K(39) and K(41):

Electrons: 19, 19
Protons: 19, 19
Neutrons: 20, 22

Isotopes: Same atomic number, different mass numbers.

Abundance percentages: 95% for the K(39) and 5% for the K(41).

Log answers: NOTE: I took 2.6 and 5.6 and I know some people took other numbers but don't worry, I'm sure there's a range.
Answers: 398 and 398x10^3

Why is it better to plot log instead of I.E directly?

Too big of a difference, hard to plot, scale problems.

First ionization energy of pottasium:
K(g)------> K+(g) and an electron






I'll post more as soon as I remember. Don't worry, I'm sure the grade boundaries won't be high. Wish you all the best of luck in your other exams!!
(edited 7 years ago)
[QUOTE="AlchemistYazan;69507854"]
Original post by Gonzalovilanova


I don't have the paper and I forgot most of the questions haha. Still, I'll try to remember some more for you :smile:.

What are 2 things commonly shared in a homologous series:
1. Functional group
2. General formula

Molar mass of ZnSO4.7H2O: 191.5 g/mol

Number of moles of sulfuric acid: 0.02 moles

Percentage yield of hydrated ZnSO4: 48%

How to prepare Pure, dry hydrated ZnSO4:
You have to try to squeeze in filtration and crystallization/evaporation in 4 marks.

Ionic equation:
Zn(s) + 2H^+ -----------> Zn^2+ and H2(g)

Observations:
1. Solid disspears
2. Bubbles of gas

Number of protons, neutrons, and electrons of K(39) and K(41):

Electrons: 19, 19
Protons: 19, 19
Neutrons: 20, 22

Isotopes: Same atomic number, different mass numbers.

Abundance percentages: 95% for the K(39) and 5% for the K(41).

Log answers: NOTE: I took 2.6 and 5.6 and I know some people took other numbers but don't worry, I'm sure there's a range.
Answers: 398 and 398x10^3

Why is it better to plot log instead of I.E directly?

Too big of a difference, hard to plot, scale problems.

First ionization energy of pottasium:
K(g)------> K+(g) and an electron






I'll post more as soon as I remember. Don't worry, I'm sure the grade boundaries won't be high. Wish you all the best of luck in your other exams!!


ur molar mass of znso4 is wrong . thus ur %age yield is wrong...
[QUOTE="ALL;69508300" Helper="Helper" OF="OF"]
Original post by AlchemistYazan


ur molar mass of znso4 is wrong . thus ur %age yield is wrong...


Oh ****, haha, I forgot to multiply O by 7 ;P! Well, no problem, I'll get CFE, I think or a mark for the method or something for the percentage yield part xD.
(edited 7 years ago)
Reply 55
It was a difficult paper tbh. The Ionisation question were pretty hard. some of the mcq were repeated. Hopingggg the grade boundaries are low.
How did you make the two skeletal formulas of cyclohexene and what name did you guys give when reacted with kmno4 and h2so4?
The log questions on the last question were a pain in the ass :mad:. Plus what did you guys get for percentage yield and the amount of hours calculated???
Original post by febxox13
It was a difficult paper tbh. The Ionisation question were pretty hard. some of the mcq were repeated. Hopingggg the grade boundaries are low.
How did you make the two skeletal formulas of cyclohexene and what name did you guys give when reacted with kmno4 and h2so4?
The log questions on the last question were a pain in the ass :mad:. Plus what did you guys get for percentage yield and the amount of hours calculated???


Don't worry, dude I'm sure you did okay. As for the yield question, I got it wrong, I think it should be 72% but I put 48%.
As for the hour question, these were my answers:
1818.2 moles
4.04x10^9 J
233.something hours
Reply 57
Original post by AlchemistYazan
Don't worry, dude I'm sure you did okay. As for the yield question, I got it wrong, I think it should be 72% but I put 48%.
As for the hour question, these were my answers:
1818.2 moles
4.04x10^9 J
233.something hours


for the question about hours, can i write the answer as 234 corr to 3 sign fig....
Reply 58
Original post by AlchemistYazan
Don't worry, dude I'm sure you did okay. As for the yield question, I got it wrong, I think it should be 72% but I put 48%.
As for the hour question, these were my answers:
1818.2 moles
4.04x10^9 J
233.something hours

I got very similar answerssssss :u:
in the MCQ there was 1 question magnesium nitride .. Was the answer C or D....

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