Find mass of product when given Kc, mass of reactant, but not volume

AI Thread Summary
To find the mass of methylcyclopentane at equilibrium given the equilibrium constant (Kc) and the initial mass of cyclohexane, the relationship Kc = [product]/[reactant] can be used. The moles of cyclohexane can be calculated from its mass, but converting to molarity is unnecessary since Kc is based on concentrations. The total mass remains constant, meaning the mass of cyclohexane that reacts will equal the mass of methylcyclopentane produced. The reaction stoichiometry indicates that the mass of cyclohexane converted to methylcyclopentane can be determined using the Kc value. Understanding these relationships allows for the calculation of the mass of the product at equilibrium.
Knight226
Messages
15
Reaction score
0

Homework Statement


Assume that at 25 C, with AlCl3 as a catalyst, the following equilibrium can be established between the liquids cyclohexane and methylcyclopentane.
C6H12 <=> C5H9CH3HCH3
Kc = 0.143
If initially 1.00 x 10^2 g cyclohexane is present, what mass of methylcyclopentane will be present in the equilibrium mixture? (Hint: Does the volume of solution matter?)

Homework Equations



Kc = [product]/[reactant]

The Attempt at a Solution


I attempted to use ICE, but since I do not know the concentration (M) for the reactants, I do not know how to proceed.
I could get the moles of cyclohexane, but then don't I need to convert it to M?

Please advice. Thank you in advance.
 
Physics news on Phys.org
HINT: Does the Volume matter?
HINT2 : Does the mass matter? In a more abstract kinda way?

The thing is :

- moles initially of molecules (Cyclohex) = moles finally (Cyclohex + metpent)
- mass initially = mass finally
- and obviously Molecular mass of hex = Mol mass of pent
Kc=mass pentane/mass hexane=moles pentane/moles hexane.

So you end up with the amount % of hex that gets turned into pent.
 
Btw what is that:
C6H12 <=> C5H9CH3HCH3

the second isn't metylcyclopentane
 
Thread 'Confusion regarding a chemical kinetics problem'
TL;DR Summary: cannot find out error in solution proposed. [![question with rate laws][1]][1] Now the rate law for the reaction (i.e reaction rate) can be written as: $$ R= k[N_2O_5] $$ my main question is, WHAT is this reaction equal to? what I mean here is, whether $$k[N_2O_5]= -d[N_2O_5]/dt$$ or is it $$k[N_2O_5]= -1/2 \frac{d}{dt} [N_2O_5] $$ ? The latter seems to be more apt, as the reaction rate must be -1/2 (disappearance rate of N2O5), which adheres to the stoichiometry of the...
I don't get how to argue it. i can prove: evolution is the ability to adapt, whether it's progression or regression from some point of view, so if evolution is not constant then animal generations couldn`t stay alive for a big amount of time because when climate is changing this generations die. but they dont. so evolution is constant. but its not an argument, right? how to fing arguments when i only prove it.. analytically, i guess it called that (this is indirectly related to biology, im...
Back
Top