Heterogenous vs. Homogenous equations

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Marni Kahn 1A
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Heterogenous vs. Homogenous equations

Postby Marni Kahn 1A » Tue Jan 07, 2020 8:44 am

What is the difference between homogenous and heterogenous equilibria?

Sam McNeill 1E
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Re: Heterogenous vs. Homogenous equations

Postby Sam McNeill 1E » Tue Jan 07, 2020 10:11 am

A homogenous equation includes substances where all of the phases are the same, for example all gases, and a heterogenous equation has a mixture of different phases.

Brian_Ho_2B
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Re: Heterogenous vs. Homogenous equations

Postby Brian_Ho_2B » Tue Jan 07, 2020 10:14 am

Another important thing to note is that when a heterogeneous reaction has reactants or products indicated as solids or pure solvents (like H2O), we must write them as "1" when we are writing an expression for K or Q. For instance, in a heterogeneous reaction with an acid HA and H2O as reactants and H3O+ and A- as products, we write K as [H3O+][A-]/[HA]. I didn't include the concentration of water because it is a pure solvent, so leave it in the denominator as 1.

Robin Cadd 1D
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Re: Heterogenous vs. Homogenous equations

Postby Robin Cadd 1D » Tue Jan 07, 2020 11:08 am

Sam McNeill 1E wrote:A homogenous equation includes substances where all of the phases are the same, for example all gases, and a heterogenous equation has a mixture of different phases.

Here's a couple of examples that I think illustrate this well:
homogeneous: N2 (g) +3 H2 (g) -> 2 NH3 (g)
heterogeneous: CaCO3 (s) -> CaO (s) + CO2 (g)

Nathan Nakaguchi 1G
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Re: Heterogenous vs. Homogenous equations

Postby Nathan Nakaguchi 1G » Tue Jan 07, 2020 11:14 am

Heterogenous equations contain compounds with different (hetero) phases while homogenous equations contain the same (homo) phases. For example a chemical equation with all of the compounds in the gas phase is homogenous.

stephaniekim2K
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Re: Heterogenous vs. Homogenous equations

Postby stephaniekim2K » Tue Jan 07, 2020 11:15 am

Homogeneous equations are all in the same state of matter, while heterogeneous are in mixed states of matter.

Mitchell Koss 4G
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Re: Heterogenous vs. Homogenous equations

Postby Mitchell Koss 4G » Tue Jan 07, 2020 11:40 am

And remember that terms in reactions that are solids or pure liquids are left out of the equilibrium constant.


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