## 11.13

$PV=nRT$

Sammy Thatipelli 1B
Posts: 63
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### 11.13

Why does a have the answer 1/PBCl3^2, instead of just writing PBCL3^2? Why is the inverse partial pressure the correct answer in this case? Because in b, the answer is just the two aqueous concentrations multiplied together, without any inverse equation. Can someone explain how to do part a in terms of why it is 1 over the concentration of BCL3

Alex Leve 3F
Posts: 20
Joined: Fri Sep 29, 2017 7:07 am

### Re: 11.13

These reaction quotient expressions always involve products over reactants, but excluding solids and liquids. In a, the products are only solids so the numerator is just 1, while the denominator is the gaseous reactant raised to its coefficient (2) in the chemical reaction. In b, both products are aqueous, so the numerator is both of these products multiplied by each other, raised to their respective coefficients. Since the reactants are a liquid and a solid (no aqueous or gaseous reactants), the denominator of the expression is just 1.

AtreyiMitra2L
Posts: 169
Joined: Fri Sep 29, 2017 7:03 am
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### Re: 11.13

1 is in the numerator because the products always go over the reactants. If you take the reciprocal of this, you get k for the opposite reaction.