This discussion is now closed.
Check out other Related discussions
- Alevel Chemistry
- help
- HELP im horrible at module 2 OCR chemistry
- a level biology and chemustry
- A2 Chemistry Help
- Converting CIE A-Level grades to 4.0 Scale GPA
- Btec applied science unit 5 January 2024
- Bath Mpharm Interview Questions
- Calculations
- Lattice enthalpy A2 chem question!
- Is Chemistry better at A-level than at GCSE?
- AS Chemistry Paper 1 2022
- how can i put my chemstry aqa a level grade up from a c to an a?
- about biomedical science
- SQA Higher Chemistry
- Physics for Oxford Chemistry?
- Are calculators with a solar panel allowed into the exam?
- AS/A Level Chemistry Study Group 2023/2024
- pls be my chemistry tutor !!
- I want to study astrophysics but need help picking A-levels
A2 chemistry calculation
A sample of verdigris has the formula [(CH3COO)2Cu]2.Cu(OH)2.xH2O
Analysis of the sample shows that it contains 16.3% water by mass.
Calculate the value of x in the formula
Now i asked someone to help me on this and their answer came it to be x = 4 (rounded up). I just want to see if someone who knows this inside out can tell me if they reach that same answer and if they do tell me in detail how you got to that answer.
Thank you in advance. Please quote with help asap.
Analysis of the sample shows that it contains 16.3% water by mass.
Calculate the value of x in the formula
Now i asked someone to help me on this and their answer came it to be x = 4 (rounded up). I just want to see if someone who knows this inside out can tell me if they reach that same answer and if they do tell me in detail how you got to that answer.
Thank you in advance. Please quote with help asap.
I got 4 as well.
You have to set up an equation. The molecular mass of the compound is 379.5+18x (where x is the number of water molecules) We know that 16.3% of this mass is water, therefore (379.5+18x)*0.163=18x
If you solve the equation and round the result you get 4 for x.
You have to set up an equation. The molecular mass of the compound is 379.5+18x (where x is the number of water molecules) We know that 16.3% of this mass is water, therefore (379.5+18x)*0.163=18x
If you solve the equation and round the result you get 4 for x.
Mangaartist
I got 4 as well.
You have to set up an equation. The molecular mass of the compound is 379.5+18x (where x is the number of water molecules) We know that 16.3% of this mass is water, therefore (379.5+18x)*0.163=18x
If you solve the equation and round the result you get 4 for x.
You have to set up an equation. The molecular mass of the compound is 379.5+18x (where x is the number of water molecules) We know that 16.3% of this mass is water, therefore (379.5+18x)*0.163=18x
If you solve the equation and round the result you get 4 for x.
Why does it equal 18x and not the total of the masses?
boromir9111
Why does it equal 18x and not the total of the masses?
Because the left side of the equation is the mass of water in the compound (16.3% of the total mass) so the right side also has to be equal to the mass of water in the compound.
boromir9111
Hey there, i was hoping you could help me with this one final problem please.
A sample of verdigris has the formula [(CH3COO)2Cu]2.Cu(OH)2.xH2O
Analysis of the sample shows that it contains 16.3% water by mass.
Calculate the value of x in the formula
My friend tells me the answer is x = 4, i was wondering if you could check if that's right and if it is or not please tell me how you got to your answer and explain in detail please.
Quote with help asap please.
A sample of verdigris has the formula [(CH3COO)2Cu]2.Cu(OH)2.xH2O
Analysis of the sample shows that it contains 16.3% water by mass.
Calculate the value of x in the formula
My friend tells me the answer is x = 4, i was wondering if you could check if that's right and if it is or not please tell me how you got to your answer and explain in detail please.
Quote with help asap please.
You need to use (mass of water)/(total mass) x 100 = %mass of water
So 18x/(460.5 + 18x) x 100 = 16.3
=> 18x = 0.163 x (460.5 + 18x)
=> x = 5
check: [(18 x 5)/(550.5)] x 100 = 16.3%
You need to use (mass of water)/(total mass) x 100 = %mass of water
So 18x/(460.5 + 18x) x 100 = 16.3
=> 18x = 0.163 x (460.5 + 18x)
=> x = 5
That is a method used by someone who just quoted me and his answer differs but his makes much more sense to the one above and how my friend did it. I will use this explanation but thank you for your help.
So 18x/(460.5 + 18x) x 100 = 16.3
=> 18x = 0.163 x (460.5 + 18x)
=> x = 5
That is a method used by someone who just quoted me and his answer differs but his makes much more sense to the one above and how my friend did it. I will use this explanation but thank you for your help.
boromir9111
You need to use (mass of water)/(total mass) x 100 = %mass of water
So 18x/(460.5 + 18x) x 100 = 16.3
=> 18x = 0.163 x (460.5 + 18x)
=> x = 5
So 18x/(460.5 + 18x) x 100 = 16.3
=> 18x = 0.163 x (460.5 + 18x)
=> x = 5
That is good as well, mine would be good too but I apparently miscalculated the molecular mass
EierVonSatan
You need to use (mass of water)/(total mass) x 100 = %mass of water
So 18x/(460.5 + 18x) x 100 = 16.3
=> 18x = 0.163 x (460.5 + 18x)
=> x = 5
check: [(18 x 5)/(550.5)] x 100 = 16.3%
So 18x/(460.5 + 18x) x 100 = 16.3
=> 18x = 0.163 x (460.5 + 18x)
=> x = 5
check: [(18 x 5)/(550.5)] x 100 = 16.3%
Yep, it does equal 16.3%. Thank you again for your help, it's good to know if i need a good explanation i should rely on TSR and not my friends lol. Another question, do you have a degree in chem or currently studying chem at uni?
EierVonSatan
You're welcome.
Both
I am a PhD student in chemistry
Both
I am a PhD student in chemistry
Excellent, so there's another problem bugging me for the A2 topic on "unifying concepts" it's the rate determining step, i looked over the book again and again and did some exam questions, there's very little on it but i like to cover my ground so i know in depth. If it's not too much trouble can you explain how you would tackle a question relating RDS, please?
boromir9111
Excellent, so there's another problem bugging me for the A2 topic on "unifying concepts" it's the rate determining step, i looked over the book again and again and did some exam questions, there's very little on it but i like to cover my ground so i know in depth. If it's not too much trouble can you explain how you would tackle a question relating RDS, please?
I think that you need to be a little more specific with the question.
RDS is normally elucidated from the rate equation and the proposed mechanisms of reaction.
charco
I think that you need to be a little more specific with the question.
RDS is normally elucidated from the rate equation and the proposed mechanisms of reaction.
RDS is normally elucidated from the rate equation and the proposed mechanisms of reaction.
Oh, no problem. I know what it means, If it's in the rate equation or something derived from it, it will appear in the slow step (rate determining step).
Let's say for example the rate equation = k[A]^2
What would be the slow step and if possible include the following steps as well.
boromir9111
Oh, no problem. I know what it means, If it's in the rate equation or something derived from it, it will appear in the slow step (rate determining step).
Let's say for example the rate equation = k[A]^2
What would be the slow step and if possible include the following steps as well.
Let's say for example the rate equation = k[A]^2
What would be the slow step and if possible include the following steps as well.
Maybe it would be easier to direct you to this thread
http://www.thestudentroom.co.uk/showthread.php?t=1077686
read it first and then come back with questions
Related discussions
- Alevel Chemistry
- help
- HELP im horrible at module 2 OCR chemistry
- a level biology and chemustry
- A2 Chemistry Help
- Converting CIE A-Level grades to 4.0 Scale GPA
- Btec applied science unit 5 January 2024
- Bath Mpharm Interview Questions
- Calculations
- Lattice enthalpy A2 chem question!
- Is Chemistry better at A-level than at GCSE?
- AS Chemistry Paper 1 2022
- how can i put my chemstry aqa a level grade up from a c to an a?
- about biomedical science
- SQA Higher Chemistry
- Physics for Oxford Chemistry?
- Are calculators with a solar panel allowed into the exam?
- AS/A Level Chemistry Study Group 2023/2024
- pls be my chemistry tutor !!
- I want to study astrophysics but need help picking A-levels
Latest
Trending
Last reply 1 week ago
Im confused about this chemistry question, why does it form these productsTrending
Last reply 1 week ago
Im confused about this chemistry question, why does it form these products
