Extremely troubled!
I'm carrying out an investigation into the effect of manganese oxide (my solid catalyst) on the rate of decomposition of hydrogen peroxide, and then the effect of temperature on the activation energy.
To investigate this, I'm measuring the amount of O2 gas producted at regular intervals to determine the rate, and order of reaction by changing the concentration of h202 and then changing the mass of my solid catalyst. Using these, i'll hope to find K (my rate constant) which will be used in the Arrhenius equation.
My rate is measured in cm^3(o2)s^-1
I am changing the concentration of h202... It is measured in vol but i can easily convert this into moldm^-3
however, my catalyst is measured in grams!
However, for the purposes of rate equations I heard that the rate of a reaction is measured in terms of how fast the concentration of one of the reactants is falling. (Its units are mol dm-3 s-1.) I'm measuring the amount of gas given off.. will this work?
rate= k[A]^a[B]^b where B is the concentration of manganese dioxide in moldm-3.. my catalyst is a solid! Ahhhhh... If I plug in my reactant in grams, will this still work?
Or am i getting stressed over nothing?
To investigate this, I'm measuring the amount of O2 gas producted at regular intervals to determine the rate, and order of reaction by changing the concentration of h202 and then changing the mass of my solid catalyst. Using these, i'll hope to find K (my rate constant) which will be used in the Arrhenius equation.
My rate is measured in cm^3(o2)s^-1
I am changing the concentration of h202... It is measured in vol but i can easily convert this into moldm^-3
however, my catalyst is measured in grams!
However, for the purposes of rate equations I heard that the rate of a reaction is measured in terms of how fast the concentration of one of the reactants is falling. (Its units are mol dm-3 s-1.) I'm measuring the amount of gas given off.. will this work?
rate= k[A]^a[B]^b where B is the concentration of manganese dioxide in moldm-3.. my catalyst is a solid! Ahhhhh... If I plug in my reactant in grams, will this still work?
Or am i getting stressed over nothing?
bump.
nobody?
[QUOTE="Symphony;36248224" Simple="Simple"]I'm carrying out an investigation into the effect of manganese oxide (my solid catalyst) on the rate of decomposition of hydrogen peroxide, and then the effect of temperature on the activation energy.
To investigate this, I'm measuring the amount of O2 gas producted at regular intervals to determine the rate, and order of reaction by changing the concentration of h202 and then changing the mass of my solid catalyst. Using these, i'll hope to find K (my rate constant) which will be used in the Arrhenius equation.
My rate is measured in cm^3(o2)s^-1
I am changing the concentration of h202... It is measured in vol but i can easily convert this into moldm^-3
however, my catalyst is measured in grams!
However, for the purposes of rate equations I heard that the rate of a reaction is measured in terms of how fast the concentration of one of the reactants is falling. (Its units are mol dm-3 s-1.) I'm measuring the amount of gas given off.. will this work?
rate= k[A]^a^b where B is the concentration of manganese dioxide in moldm-3.. my catalyst is a solid! Ahhhhh... If I plug in my reactant in grams, will this still work?
Or am i getting stressed over nothing?
You cannot apply the rate equation to solids - they have no concentration.
You can still carry out an investigation to find the dependency of the rate on catalyst mass.
The rate of volume of gas produced is directly proportional to the concentration of hydrogen peroxide used up and can be used as a measure of the rate.
To investigate this, I'm measuring the amount of O2 gas producted at regular intervals to determine the rate, and order of reaction by changing the concentration of h202 and then changing the mass of my solid catalyst. Using these, i'll hope to find K (my rate constant) which will be used in the Arrhenius equation.
My rate is measured in cm^3(o2)s^-1
I am changing the concentration of h202... It is measured in vol but i can easily convert this into moldm^-3
however, my catalyst is measured in grams!
However, for the purposes of rate equations I heard that the rate of a reaction is measured in terms of how fast the concentration of one of the reactants is falling. (Its units are mol dm-3 s-1.) I'm measuring the amount of gas given off.. will this work?
rate= k[A]^a^b where B is the concentration of manganese dioxide in moldm-3.. my catalyst is a solid! Ahhhhh... If I plug in my reactant in grams, will this still work?
Or am i getting stressed over nothing?
You cannot apply the rate equation to solids - they have no concentration.
You can still carry out an investigation to find the dependency of the rate on catalyst mass.
The rate of volume of gas produced is directly proportional to the concentration of hydrogen peroxide used up and can be used as a measure of the rate.
Original post by charco
You cannot apply the rate equation to solids - they have no concentration.
You can still carry out an investigation to find the dependency of the rate on catalyst mass.
The rate of volume of gas produced is directly proportional to the concentration of hydrogen peroxide used up and can be used as a measure of the rate.
You can still carry out an investigation to find the dependency of the rate on catalyst mass.
The rate of volume of gas produced is directly proportional to the concentration of hydrogen peroxide used up and can be used as a measure of the rate.
Ah right, thanks.
Is there an alternative way to carry out the rate constant and then activation enthalpy? One of the aims of my investigation given by OCR Salters is to "Find the activation enthalpies with different catalysts" (manganese dioxide and catalase) hence I thought this was somehow possible?
Original post by Simple Symphony
Ah right, thanks.
Is there an alternative way to carry out the rate constant and then activation enthalpy? One of the aims of my investigation given by OCR Salters is to "Find the activation enthalpies with different catalysts" (manganese dioxide and catalase) hence I thought this was somehow possible?
Is there an alternative way to carry out the rate constant and then activation enthalpy? One of the aims of my investigation given by OCR Salters is to "Find the activation enthalpies with different catalysts" (manganese dioxide and catalase) hence I thought this was somehow possible?
You just find the rate equation in terms of hydrogen peroxide and then determine (by experiment) the rate constant at different temperatures. Finally you apply Arrhenius to obtain the Ea.
Original post by charco
You just find the rate equation in terms of hydrogen peroxide and then determine (by experiment) the rate constant at different temperatures. Finally you apply Arrhenius to obtain the Ea.
Ah okay, so I should completely disregard manganese (IV) oxide from the rate equation and carry on from there (I don't have to find the order of reaction with respect to Mn02)? And in other words, varying the mass of the catalyst has no effect on the rate constant in the rate equation?
Sorry, i'm still slightly confused but you're a lifesaver!
Original post by Simple Symphony
Ah okay, so I should completely disregard manganese (IV) oxide from the rate equation and carry on from there (I don't have to find the order of reaction with respect to Mn02)? And in other words, varying the mass of the catalyst has no effect on the rate constant in the rate equation?
Sorry, i'm still slightly confused but you're a lifesaver!
Sorry, i'm still slightly confused but you're a lifesaver!
The manganese dioxide does affect the rate constant, you know that because it's a catalyst. However you cannot produce a rate equation for it, as it does not have a concentration - it's a solid.
The best way forward is to keep the manganese(IV) oxide constant and vary the hydrogen peroxide. This way the effect of the manganese(IV) oxide is factored into the rate constant.
You then find out the order wrt to hydrogen peroxide and, from this, values of the rate constant at different temperatures.
Original post by charco
The manganese dioxide does affect the rate constant, you know that because it's a catalyst. However you cannot produce a rate equation for it, as it does not have a concentration - it's a solid.
The best way forward is to keep the manganese(IV) oxide constant and vary the hydrogen peroxide. This way the effect of the manganese(IV) oxide is factored into the rate constant.
You then find out the order wrt to hydrogen peroxide and, from this, values of the rate constant at different temperatures.
The best way forward is to keep the manganese(IV) oxide constant and vary the hydrogen peroxide. This way the effect of the manganese(IV) oxide is factored into the rate constant.
You then find out the order wrt to hydrogen peroxide and, from this, values of the rate constant at different temperatures.
Right, got it.. Thanks a lot Charco, i've been wracking my brain for days - I know it seems tedious but oh well!
I have the same problem, i wanted to find out the rate equation for the catalytic decomposition of hydrogen peroxide using a solid catalyst (Manganese(IV)Oxide and Lead(II)Oxide.
Can I write the rate equation as follows? rate = k(h202)(MnO)
Also if I wanted to find out the rate constant is there any way to do this?
Can I write the rate equation as follows? rate = k(h202)(MnO)
Also if I wanted to find out the rate constant is there any way to do this?
Original post by Simple Symphony
bump.
Hi, im having a problem
my rate is in cm3s-1 but my teachers said i need to change it to moldm3s-1 i can do this and obtain the rates at different conc of h202
now here comes the problem i know i need to work out my rate constant values at different temps but im not sure how to obtain the rates (my previous method was same conc and catalyts just different temps)
How did you go about yours?
Many thanks
Quick Reply
Related discussions
- internal exclusion uni
- Law degree
- crying on period
- Did something stupid.
- Emotional dysregulation and it's effect on relationships
- Why do I get so irritated when my friend doesn't do her homework
- Changing test date
- NCS this summer
- why do I hate humans so much?
- Stage 3 Fitness to Study Conference
- chat gpt is incredible… too good to be true?
- I can’t get through (existing application)
- I need help
- SOAS: Human Rights Law (MA)
- Cambridge College best for law (+ extra considerations)
- The way my mum treats me specifically when she started uni. BTW i have INATTENTIVE AD
- Are tube tops inappropriate
- English Literature AQA COMEDY
- Edexcel English Lit Paper 1: Macbeth Section A, Question 1: Grade 9 Answer?
- why can't I square both sides of the inequality in the case?
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
