## 5G11

Jina Kwon
Posts: 100
Joined: Fri Aug 09, 2019 12:15 am

### 5G11

For question 5G11, why are some answers written with P and why are some answers written with brackets?

Brian_Ho_2B
Posts: 221
Joined: Fri Aug 09, 2019 12:16 am

### Re: 5G11

The answers written with P are the expressions of the ratio of the reactants and products' partial pressures whereas those with brackets represent concentrations of the reactants and products. K values or Q values written with P are usually used for equations with gases while those written with concentrations are usually used for aqueous solutions.

Kallista McCarty 1C
Posts: 212
Joined: Wed Sep 18, 2019 12:18 am

### Re: 5G11

P is used to represent partial pressures of gasses while the brackets represent concentration (molarity, mol/L)

Michelle N - 2C
Posts: 117
Joined: Wed Sep 18, 2019 12:19 am

### Re: 5G11

Jina Kwon wrote:For question 5G11, why are some answers written with P and why are some answers written with brackets?

Hi! I just wanted to add another question to this same problem because I'm confused when looking at the answers. How do we know if they're asking for partial pressure or concentration? Is there a way to tell if they're asking specifically for pressure or concentration?

Justin Sarquiz 2F
Posts: 106
Joined: Fri Aug 30, 2019 12:15 am

### Re: 5G11

You would use partial pressure for equation with gases and concentration for equations in aqueous solution. Technically, writing the answer with concentration instead of partial pressure is the same thing I believe. But in problems where you have to solve for K, the problem would give you either concentration or partial pressure, so you would know when to use Kc or Kp.

Subashni Rajiv 1K
Posts: 101
Joined: Wed Sep 18, 2019 12:16 am

### Re: 5G11

For part b, the reactant concentrations are excluded because they are in the solid and liquid forms.