Frankiitch
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#1
Add to this// correct
I'm not sure of the order xx Franceska

1(a) how does rain water become hard?
It comes in contact with rocks and ions that cause hardness dissolve in it

(B) describe pattern
Higher the temperature higher the solubility until 68•C where max solubility is 59g/100g then higher the temp lower the solubility
+ use data from the graph

(C) how ion exchange column works?
Has hydrogen and sodium ions that exchange places with calcium and magnesium ions in hard water. Hence they soften it as they remove ions that cause hardness

2(a) methanol? CH3OH (first box)

(B) overall energy change? C (third one) from reactant line down to product energy line

3- calorimetry experiment (6 marks)


(B) how to increase accuracy of results?
Add insulation to glass beaker or add a lid to reduce heat loss. Use digital thermometer reduce measurement error as easier to read and stores data.

4 equilibrium reaction questions
(a) balance equation
(B) why moderately high temperature is used instead of lower temperature? (3marks)

Lower temp would increase yield of product as forward reaction is exothermic. However would result in a low rate of reaction due to less kinetic energy and collisions. This is costly in industry

Higher temp would reduce yield of product as forward reaction is exothemic so equilibrium shifts to favour reverse reaction.

Comprimise temperature- not too high for low yield of product. Not to low that slow rate of reaction

(C)why high pressure? (2marks)
Less molecules in products, so equilibrium shifts to favour forward as this reduces the pressure. Higher yield of product so more profit

(D) describe titaration? (5marks)
Acid in conical flask using pipette. Add universal indicator to flask - phenolphthalien (e.g) alkali in burette using pipette. Measure volume. White tile under flask. Add alkali to acid drop by drop. Swirl flask regularly. When colour change measure final volume in burette. Calculate volume of alkali used to neutralise acid. Repeat till titres within 0.5cm3

(e) caluculate concentration of acid
0.21mol/dm3


5- ion tests

(a) Iodide solution - yellow precipitate
(b) Iron (II) green precipitate
(c) why is it hard to distinguish both potassium and sodium ions? The yellow flame from sodium ions is brighter than lilac flame from potassium so obscures it // colours mix together so it's hard to distinguish which ions present

(d) how would you use sodium hydroxide to test whether aluminium or magnesium ions present?
Add excess, if aluminium ion present the white precipitate will redissolve in excess and solution will return to clear

6- energy changes

(a) energy change

(-)81kj

(b) why exothermic? Energy released in bond forming in products is greater than energy needed in bond breaking in reactants hence energy is released to surroundings



** if you know the marks available for each question add this

** if I've missed any questions add them in

** these are simply my answers so if I've made any mistakes please correct me


Extra question on periodic table

(a) why did Mendeleev leave gaps? So he could put elements with similar properties together// leave gaps for undiscovered elements


(B) why the elements were in the wrong place?
They are metal and have different properties t other elements in that group

(c)why bromine in group 7?
7 electrons in outer shell

(D) why bromine more reactive?
Less shells. Less distance between nucleus and outer electron, less shielding. Stronger electrostatic forces of attraction hence incoming electron is more easily gained
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Frankiitch
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#2
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#2
There was another question on the reaction of potassium and water
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king_english
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#3
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#3
(Original post by Frankiitch)
Add to this// correct
I'm not sure of the order xx Franceska

1(a) how does rain water become hard?
It comes in contact with rocks and ions that cause hardness dissolve in it

(B) describe pattern
Higher the temperature higher the solubility until 68•C where max solubility is 59g/100g then higher the temp lower the solubility
+ use data from the graph

(C) how ion exchange column works?
Has hydrogen and sodium ions that exchange places with calcium and magnesium ions in hard water. Hence they soften it as they remove ions that cause hardness

2(a) methanol? CH3OH (first box)

(B) overall energy change? C (third one) from reactant line down to product energy line

3- calorimetry experiment (6 marks)


(B) how to increase accuracy of results?
Add insulation to glass beaker or add a lid to reduce heat loss. Use digital thermometer reduce measurement error as easier to read and stores data.

4 equilibrium reaction questions
(a) balance equation
(B) why moderately high temperature is used instead of lower temperature? (3marks)

Lower temp would increase yield of product as forward reaction is exothermic. However would result in a low rate of reaction due to less kinetic energy and collisions. This is costly in industry

Higher temp would reduce yield of product as forward reaction is exothemic so equilibrium shifts to favour reverse reaction.

Comprimise temperature- not too high for low yield of product. Not to low that slow rate of reaction

(C)why high pressure? (2marks)
Less molecules in products, so equilibrium shifts to favour forward as this reduces the pressure. Higher yield of product so more profit

(D) describe titaration? (5marks)
Acid in conical flask using pipette. Add universal indicator to flask - phenolphthalien (e.g) alkali in burette using pipette. Measure volume. White tile under flask. Add alkali to acid drop by drop. Swirl flask regularly. When colour change measure final volume in burette. Calculate volume of alkali used to neutralise acid. Repeat till titres within 0.5cm3

(e) caluculate concentration of acid
0.21mol/dm3


5- ion tests

(a) Iodide solution - yellow precipitate
(b) Iron (II) green precipitate
(c) why is it hard to distinguish both potassium and sodium ions? The yellow flame from sodium ions is brighter than lilac flame from potassium so obscures it // colours mix together so it's hard to distinguish which ions present

(d) how would you use sodium hydroxide to test whether aluminium or magnesium ions present?
Add excess, if aluminium ion present the white precipitate will redissolve in excess and solution will return to clear

6- energy changes

(a) energy change

(-)81kj

(b) why exothermic? Energy released in bond forming in products is greater than energy needed in bond breaking in reactants hence energy is released to surroundings



** if you know the marks available for each question add this

** if I've missed any questions add them in

** these are simply my answers so if I've made any mistakes please correct me


Extra question on periodic table

(a) why did Mendeleev leave gaps? So he could put elements with similar properties together// leave gaps for undiscovered elements


(B) why the elements were in the wrong place?
They are metal and have different properties t other elements in that group

(c)why bromine in group 7?
7 electrons in outer shell

(D) why bromine more reactive?

More shells. Greater distance between nucleus and outer electron, more shielding. Weaker electrostatic forces of attraction hence outer electron is more easily lost
You missed out the one about why low pressure is an advantage, which is because no pressurized sealed vessels are needed which are dangerous and expensive.
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Frankiitch
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#4
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#4
(Original post by king_english)
You missed out the one about why low pressure is an advantage, which is because no pressurized sealed vessels are needed which are dangerous and expensive.
Oh yeah thankyou, I'm sure I got this question wrong

I put atmospheric pressure is easier to obtain than high pressure
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Domsebhill
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#5
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#5
(Original post by Frankiitch)
Add to this// correct
I'm not sure of the order xx Franceska

1(a) how does rain water become hard?
It comes in contact with rocks and ions that cause hardness dissolve in it

(B) describe pattern
Higher the temperature higher the solubility until 68•C where max solubility is 59g/100g then higher the temp lower the solubility
+ use data from the graph

(C) how ion exchange column works?
Has hydrogen and sodium ions that exchange places with calcium and magnesium ions in hard water. Hence they soften it as they remove ions that cause hardness

2(a) methanol? CH3OH (first box)

(B) overall energy change? C (third one) from reactant line down to product energy line

3- calorimetry experiment (6 marks)


(B) how to increase accuracy of results?
Add insulation to glass beaker or add a lid to reduce heat loss. Use digital thermometer reduce measurement error as easier to read and stores data.

4 equilibrium reaction questions
(a) balance equation
(B) why moderately high temperature is used instead of lower temperature? (3marks)

Lower temp would increase yield of product as forward reaction is exothermic. However would result in a low rate of reaction due to less kinetic energy and collisions. This is costly in industry

Higher temp would reduce yield of product as forward reaction is exothemic so equilibrium shifts to favour reverse reaction.

Comprimise temperature- not too high for low yield of product. Not to low that slow rate of reaction

(C)why high pressure? (2marks)
Less molecules in products, so equilibrium shifts to favour forward as this reduces the pressure. Higher yield of product so more profit

(D) describe titaration? (5marks)
Acid in conical flask using pipette. Add universal indicator to flask - phenolphthalien (e.g) alkali in burette using pipette. Measure volume. White tile under flask. Add alkali to acid drop by drop. Swirl flask regularly. When colour change measure final volume in burette. Calculate volume of alkali used to neutralise acid. Repeat till titres within 0.5cm3

(e) caluculate concentration of acid
0.21mol/dm3


5- ion tests

(a) Iodide solution - yellow precipitate
(b) Iron (II) green precipitate
(c) why is it hard to distinguish both potassium and sodium ions? The yellow flame from sodium ions is brighter than lilac flame from potassium so obscures it // colours mix together so it's hard to distinguish which ions present

(d) how would you use sodium hydroxide to test whether aluminium or magnesium ions present?
Add excess, if aluminium ion present the white precipitate will redissolve in excess and solution will return to clear

6- energy changes

(a) energy change

(-)81kj

(b) why exothermic? Energy released in bond forming in products is greater than energy needed in bond breaking in reactants hence energy is released to surroundings



** if you know the marks available for each question add this

** if I've missed any questions add them in

** these are simply my answers so if I've made any mistakes please correct me


Extra question on periodic table

(a) why did Mendeleev leave gaps? So he could put elements with similar properties together// leave gaps for undiscovered elements


(B) why the elements were in the wrong place?
They are metal and have different properties t other elements in that group

(c)why bromine in group 7?
7 electrons in outer shell

(D) why bromine more reactive?

More shells. Greater distance between nucleus and outer electron, more shielding. Weaker electrostatic forces of attraction hence outer electron is more easily lost
wouldn't bromine be more reactive as its got stronger electrostatic forces so would gain an electron easier? its a halogen not an alkali metal.
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Illymoha
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#6
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#6
Omdss I wrote 0.21 and rubbed it out ffs I'm pissed and the titration question I got completely wrong 😰
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sivthasan
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#7
For 4a, you can also say that the potassium reaction produces a lilac flame.
I'm so happy about this paper, I think I only dropped 2 or 3 marks on it
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steven yeun
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#8
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#8
(Original post by Frankiitch)
Add to this// correct
I'm not sure of the order xx Franceska

1(a) how does rain water become hard?
It comes in contact with rocks and ions that cause hardness dissolve in it

(B) describe pattern
Higher the temperature higher the solubility until 68•C where max solubility is 59g/100g then higher the temp lower the solubility
+ use data from the graph

(C) how ion exchange column works?
Has hydrogen and sodium ions that exchange places with calcium and magnesium ions in hard water. Hence they soften it as they remove ions that cause hardness

2(a) methanol? CH3OH (first box)

(B) overall energy change? C (third one) from reactant line down to product energy line

3- calorimetry experiment (6 marks)


(B) how to increase accuracy of results?
Add insulation to glass beaker or add a lid to reduce heat loss. Use digital thermometer reduce measurement error as easier to read and stores data.

4 equilibrium reaction questions
(a) balance equation
(B) why moderately high temperature is used instead of lower temperature? (3marks)

Lower temp would increase yield of product as forward reaction is exothermic. However would result in a low rate of reaction due to less kinetic energy and collisions. This is costly in industry

Higher temp would reduce yield of product as forward reaction is exothemic so equilibrium shifts to favour reverse reaction.

Comprimise temperature- not too high for low yield of product. Not to low that slow rate of reaction

(C)why high pressure? (2marks)
Less molecules in products, so equilibrium shifts to favour forward as this reduces the pressure. Higher yield of product so more profit

(D) describe titaration? (5marks)
Acid in conical flask using pipette. Add universal indicator to flask - phenolphthalien (e.g) alkali in burette using pipette. Measure volume. White tile under flask. Add alkali to acid drop by drop. Swirl flask regularly. When colour change measure final volume in burette. Calculate volume of alkali used to neutralise acid. Repeat till titres within 0.5cm3

(e) caluculate concentration of acid
0.21mol/dm3


5- ion tests

(a) Iodide solution - yellow precipitate
(b) Iron (II) green precipitate
(c) why is it hard to distinguish both potassium and sodium ions? The yellow flame from sodium ions is brighter than lilac flame from potassium so obscures it // colours mix together so it's hard to distinguish which ions present

(d) how would you use sodium hydroxide to test whether aluminium or magnesium ions present?
Add excess, if aluminium ion present the white precipitate will redissolve in excess and solution will return to clear

6- energy changes

(a) energy change

(-)81kj

(b) why exothermic? Energy released in bond forming in products is greater than energy needed in bond breaking in reactants hence energy is released to surroundings



** if you know the marks available for each question add this

** if I've missed any questions add them in

** these are simply my answers so if I've made any mistakes please correct me


Extra question on periodic table

(a) why did Mendeleev leave gaps? So he could put elements with similar properties together// leave gaps for undiscovered elements


(B) why the elements were in the wrong place?
They are metal and have different properties t other elements in that group

(c)why bromine in group 7?
7 electrons in outer shell

(D) why bromine more reactive?

More shells. Greater distance between nucleus and outer electron, more shielding. Weaker electrostatic forces of attraction hence outer electron is more easily lost
Also an advantage and disadvantage on hard water
Advantage - contains calcium which is goodnfor development and maintenance of bones
Disadvantage - reduces efficiency when boiled because it forms scale (i think???) on the heating elements
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mabeljessica
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#9
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#9
(Original post by steven yeun)
Also an advantage and disadvantage on hard water
Advantage - contains calcium which is goodnfor development and maintenance of bones
Disadvantage - reduces efficiency when boiled because it forms scale (i think???) on the heating elements
I also said that for hard water a disadvantage was that it does not lather as well so you have to buy more soap which costs money.
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PepeIsAngry
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For the last one, do you mean that the outer electron is less easily gained? Because halogens have 7 electrons on the outer shell. May be confusing it with Group 1 metals.
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steven yeun
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#11
(Original post by mabeljessica)
I also said that for hard water a disadvantage was that it does not lather as well so you have to buy more soap which costs money.
yeah i think that should get the mark too
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Frankiitch
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#12
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#12
(Original post by Domsebhill)
wouldn't bromine be more reactive as its got stronger electrostatic forces so would gain an electron easier? its a halogen not an alkali metal.
Omg 😭😭😭 I got this completely wrong. But I know the content but I made a silly mistake 😭 Yeah weaker electrostatic forces mean an electron is less easily gained
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Frankiitch
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#13
(Original post by PepeIsAngry)
For the last one, do you mean that the outer electron is less easily gained? Because halogens have 7 electrons on the outer shell. May be confusing it with Group 1 metals.
How many marks was this because I wrote the counterargument so I got it completely wrong
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username2931236
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(Original post by Frankiitch)
How many marks was this because I wrote the counterargument so I got it completely wrong
think it was 3 marks. don't worry
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PepeIsAngry
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I think it was 3 or 2 as well, they allow converse arguments for some questions too as they finalise the mark scheme after so I don't think you will lose marks for that.
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EGK
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Outer electron is further away from the nucleus. Weak attraction to the nucleus. More shielding by inner electrons and so electrons are gained easily. This is what I wrote about bromine, is it right?
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Bluefish X
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#17
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#17
(Original post by Frankiitch)
Add to this// correct
I'm not sure of the order xx Franceska

1(a) how does rain water become hard?
It comes in contact with rocks and ions that cause hardness dissolve in it

(B) describe pattern
Higher the temperature higher the solubility until 68•C where max solubility is 59g/100g then higher the temp lower the solubility
+ use data from the graph

(C) how ion exchange column works?
Has hydrogen and sodium ions that exchange places with calcium and magnesium ions in hard water. Hence they soften it as they remove ions that cause hardness

2(a) methanol? CH3OH (first box)

(B) overall energy change? C (third one) from reactant line down to product energy line

3- calorimetry experiment (6 marks)


(B) how to increase accuracy of results?
Add insulation to glass beaker or add a lid to reduce heat loss. Use digital thermometer reduce measurement error as easier to read and stores data.

4 equilibrium reaction questions
(a) balance equation
(B) why moderately high temperature is used instead of lower temperature? (3marks)

Lower temp would increase yield of product as forward reaction is exothermic. However would result in a low rate of reaction due to less kinetic energy and collisions. This is costly in industry

Higher temp would reduce yield of product as forward reaction is exothemic so equilibrium shifts to favour reverse reaction.

Comprimise temperature- not too high for low yield of product. Not to low that slow rate of reaction

(C)why high pressure? (2marks)
Less molecules in products, so equilibrium shifts to favour forward as this reduces the pressure. Higher yield of product so more profit

(D) describe titaration? (5marks)
Acid in conical flask using pipette. Add universal indicator to flask - phenolphthalien (e.g) alkali in burette using pipette. Measure volume. White tile under flask. Add alkali to acid drop by drop. Swirl flask regularly. When colour change measure final volume in burette. Calculate volume of alkali used to neutralise acid. Repeat till titres within 0.5cm3

(e) caluculate concentration of acid
0.21mol/dm3


5- ion tests

(a) Iodide solution - yellow precipitate
(b) Iron (II) green precipitate
(c) why is it hard to distinguish both potassium and sodium ions? The yellow flame from sodium ions is brighter than lilac flame from potassium so obscures it // colours mix together so it's hard to distinguish which ions present

(d) how would you use sodium hydroxide to test whether aluminium or magnesium ions present?
Add excess, if aluminium ion present the white precipitate will redissolve in excess and solution will return to clear

6- energy changes

(a) energy change

(-)81kj

(b) why exothermic? Energy released in bond forming in products is greater than energy needed in bond breaking in reactants hence energy is released to surroundings



** if you know the marks available for each question add this

** if I've missed any questions add them in

** these are simply my answers so if I've made any mistakes please correct me


Extra question on periodic table

(a) why did Mendeleev leave gaps? So he could put elements with similar properties together// leave gaps for undiscovered elements


(B) why the elements were in the wrong place?
They are metal and have different properties t other elements in that group

(c)why bromine in group 7?
7 electrons in outer shell

(D) why bromine more reactive?

More shells. Greater distance between nucleus and outer electron, more shielding. Weaker electrostatic forces of attraction hence outer electron is more easily lost

These are my answers for some of them:
For the how to increase the accuracy of the results q I put add a lid and use a metal beaker
For the distinguishing flame colours q I put that the colours would be masked
For the q about how you would you hydrogen peroxide to test whether aluminium and magnesium ions would be present I said that the aluminium would form a colourless solution and magnesium would form white precipitate when it is added to it.
For the calculating bond energies q I put 81 but forgot to but a minus in front of it would I loose marks?

Are my answers ok/right?
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AR.27
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I got -150 for the last question?????
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username2647535
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#19
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Wait for that bromine one did you have to mention that bromine displaced iodine from an aqueous solution of its salt?
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perfectlywrecked
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#20
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#20
(Original post by AR.27)
I got -150 for the last question?????
Organic chemistry is usually where people get complete different answers, I got -81kJ, you may be right though?
What did everyone get for the concentration question? Everyone I've asked has gotten different answers...
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