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Could someone give me some practice chemistry questions?
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E.g. on titration calculations and identifying salts?
E.g. you give me a situation such as, heat a compound X, a lilac flame is produced therefore it is a potassium compound, but I have to give the answer.
E.g. you give me a situation such as, heat a compound X, a lilac flame is produced therefore it is a potassium compound, but I have to give the answer.
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#2
Um I don't know if this is what you're looking for, but here you go:
Sulphamic acid reacts with sodium hydroxide according to the following equation:
NH2S03H + NaOH ---> NH2SO3Na + H20
A standard solution of sulphamic acid was made by dissolving 5.210g of the acid in water and making the volume up to exactly 250cm3 with more water
a) Calculate the number of moles of acid used and the molarity of the acid solution.
b) In a titration, 22.6cm3 of this acid solution were required to neutralise 25.0cm3 of sodium hydroxide solution. Calculate the molarity of the sodium hydroxide solution.
Sulphamic acid reacts with sodium hydroxide according to the following equation:
NH2S03H + NaOH ---> NH2SO3Na + H20
A standard solution of sulphamic acid was made by dissolving 5.210g of the acid in water and making the volume up to exactly 250cm3 with more water
a) Calculate the number of moles of acid used and the molarity of the acid solution.
b) In a titration, 22.6cm3 of this acid solution were required to neutralise 25.0cm3 of sodium hydroxide solution. Calculate the molarity of the sodium hydroxide solution.
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#3
(Original post by Widowmaker)
E.g. on titration calculations and identifying salts?
E.g. you give me a situation such as, heat a compound X, a lilac flame is produced therefore it is a potassium compound, but I have to give the answer.
E.g. on titration calculations and identifying salts?
E.g. you give me a situation such as, heat a compound X, a lilac flame is produced therefore it is a potassium compound, but I have to give the answer.
0
(Original post by BarelyLegal)
Um I don't know if this is what you're looking for, but here you go:
Sulphamic acid reacts with sodium hydroxide according to the following equation:
NH2S03H + NaOH ---> NH2SO3Na + H20
A standard solution of sulphamic acid was made by dissolving 5.210g of the acid in water and making the volume up to exactly 250cm3 with more water
a) Calculate the number of moles of acid used and the molarity of the acid solution.
b) In a titration, 22.6cm3 of this acid solution were required to neutralise 25.0cm3 of sodium hydroxide solution. Calculate the molarity of the sodium hydroxide solution.
Um I don't know if this is what you're looking for, but here you go:
Sulphamic acid reacts with sodium hydroxide according to the following equation:
NH2S03H + NaOH ---> NH2SO3Na + H20
A standard solution of sulphamic acid was made by dissolving 5.210g of the acid in water and making the volume up to exactly 250cm3 with more water
a) Calculate the number of moles of acid used and the molarity of the acid solution.
b) In a titration, 22.6cm3 of this acid solution were required to neutralise 25.0cm3 of sodium hydroxide solution. Calculate the molarity of the sodium hydroxide solution.
5.210 grams
Molar mass = 97
No of moles = 5.210/97 = 0.0537 moles
=> 5.210/97 = (250*C)/1000
=> 5.210/97 = 0.25C
C = (4*5.210)/97 = 0.215 moldm^-3
b)
NH2S03H
V = 22.6cm3 = 0.0226dm^3
C = 0.215 moldm^-3
NaOH
V = 25.0cm3 = 0.025dm3
C = ?
At the equivalence point, the number of moles are equal.
no of moles of sulphamic acid = 0.0226*0.215 = 4.859*10^-3
=> no of moles of NaOH = 4.859*10^-3
4.859*10^-3 = 0.025C
C = 0.194moldm^-3
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(Original post by Widowmaker)
a) NH2S03H
5.210 grams
Molar mass = 97
No of moles = 5.210/97 = 0.0537 moles
=> 5.210/97 = (250*C)/1000
=> 5.210/97 = 0.25C
C = (4*5.210)/97 = 0.215 moldm^-3
b)
NH2S03H
V = 22.6cm3 = 0.0226dm^3
C = 0.215 moldm^-3
NaOH
V = 25.0cm3 = 0.025dm3
C = ?
At the equivalence point, the number of moles are equal.
no of moles of sulphamic acid = 0.0226*0.215 = 4.859*10^-3
=> no of moles of NaOH = 4.859*10^-3
4.859*10^-3 = 0.025C
C = 0.194moldm^-3
a) NH2S03H
5.210 grams
Molar mass = 97
No of moles = 5.210/97 = 0.0537 moles
=> 5.210/97 = (250*C)/1000
=> 5.210/97 = 0.25C
C = (4*5.210)/97 = 0.215 moldm^-3
b)
NH2S03H
V = 22.6cm3 = 0.0226dm^3
C = 0.215 moldm^-3
NaOH
V = 25.0cm3 = 0.025dm3
C = ?
At the equivalence point, the number of moles are equal.
no of moles of sulphamic acid = 0.0226*0.215 = 4.859*10^-3
=> no of moles of NaOH = 4.859*10^-3
4.859*10^-3 = 0.025C
C = 0.194moldm^-3
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#7
(Original post by Widowmaker)
Can someone check if this is correct? Question is above.
Can someone check if this is correct? Question is above.
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(Original post by oxymoron)
Yes it is correct as far as I can see.
Yes it is correct as far as I can see.
Do you know anything about the edexcel AS Chemistry practical?
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#9
(Original post by Widowmaker)
that's good, thankyou.
Do you know anything about the edexcel AS Chemistry practical?
that's good, thankyou.
Do you know anything about the edexcel AS Chemistry practical?
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#10
Describe the effect of a nitro-substituent on directing the site of reaction in the electrophilic substitution of an aromatic compound (e.g. benzene). Rationalise that effect by considering charge stabilisation.
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(Original post by BCHL85)
Did you do enthalpy change practice? Something like measure the temperature before and after the reaction ... then draw a graph, from it you can calculate the enthalpy change?
Did you do enthalpy change practice? Something like measure the temperature before and after the reaction ... then draw a graph, from it you can calculate the enthalpy change?
2 hours for each practical, but i'm just swotting up on these types of practicals, common mistakes and calculations.
If there are only two practicals, will there be a planning element to these practicals at all?
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#12
(Original post by ChemistBoy)
Describe the effect of a nitro-substituent on directing the site of reaction in the electrophilic substitution of an aromatic compound (e.g. benzene). Rationalise that effect by considering charge stabilisation.
Describe the effect of a nitro-substituent on directing the site of reaction in the electrophilic substitution of an aromatic compound (e.g. benzene). Rationalise that effect by considering charge stabilisation.
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(Original post by ChemistBoy)
Describe the effect of a nitro-substituent on directing the site of reaction in the electrophilic substitution of an aromatic compound (e.g. benzene). Rationalise that effect by considering charge stabilisation.
Describe the effect of a nitro-substituent on directing the site of reaction in the electrophilic substitution of an aromatic compound (e.g. benzene). Rationalise that effect by considering charge stabilisation.
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#14
(Original post by Widowmaker)
read what I am typing, I am not doing that!
read what I am typing, I am not doing that!
I made mine! I can't be bothered searching...
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#15
(Original post by TakemetoAvalon)
widomaker, where did you get your avatar? I think i might steal it
I made mine! I can't be bothered searching...
widomaker, where did you get your avatar? I think i might steal it
I made mine! I can't be bothered searching...
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#16
(Original post by BCHL85)
lol, I saw it quite familiar, is it in "spirited away" ?
lol, I saw it quite familiar, is it in "spirited away" ?
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Please don't steal my avatar.
Can anyone give me any other practice questions?
ask me questions about safety, titrations and precautions to be taken, and identifying salts (edexcel) mainly groups 1,2 and 7.
Can anyone give me any other practice questions?
ask me questions about safety, titrations and precautions to be taken, and identifying salts (edexcel) mainly groups 1,2 and 7.
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#18
(Original post by Widowmaker)
Please don't steal my avatar.
Can anyone give me any other practice questions?
ask me questions about safety, titrations and precautions to be taken, and identifying salts (edexcel) mainly groups 1,2 and 7.
Please don't steal my avatar.
Can anyone give me any other practice questions?
ask me questions about safety, titrations and precautions to be taken, and identifying salts (edexcel) mainly groups 1,2 and 7.
I'm sure you'll be fine in your practical exam. If the question is indentifying a compound , you should remember how to realise all the substance, cations, anions, gas, solid ... either by colour or smell, litmus paper, flame test, ect. Did you have the summary note of these?
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(Original post by BCHL85)
Sorry about that
I'm sure you'll be fine in your practical exam. If the question is indentifying a compound , you should remember how to realise all the substance, cations, anions, gas, solid ... either by colour or smell, litmus paper, flame test, ect. Did you have the summary note of these?
Sorry about that
I'm sure you'll be fine in your practical exam. If the question is indentifying a compound , you should remember how to realise all the substance, cations, anions, gas, solid ... either by colour or smell, litmus paper, flame test, ect. Did you have the summary note of these?
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I'm trying to see if there are any more titration precautions.
Here is my list.
Ensure that solution does not go above 0 in burette.
Check for bubbles in burette and above burette tap.
Ensure tap is closed when pouring solution into burette.
Funnel must be removed from burette after solution has been poured in.
Volumetric flask must be shaken 10-15 times to ensure solution is mixed.
I'm sure there are more obvious ones. Can you think of any?
Here is my list.
Ensure that solution does not go above 0 in burette.
Check for bubbles in burette and above burette tap.
Ensure tap is closed when pouring solution into burette.
Funnel must be removed from burette after solution has been poured in.
Volumetric flask must be shaken 10-15 times to ensure solution is mixed.
I'm sure there are more obvious ones. Can you think of any?
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