## 5% rule

Ami_Pant_4G
Posts: 106
Joined: Sat Aug 24, 2019 12:17 am

### 5% rule

When calculating the 5% ionization, if one of the reactants has a coefficient, of two for example, should the % ionization be 2x/initial x 100%? Thanks in advance

Aliya Jain 2B
Posts: 101
Joined: Wed Sep 11, 2019 12:16 am

### Re: 5% rule

Yes I believe it's the change in reactant concentration, so you would take into account coefficients.

805394719
Posts: 104
Joined: Wed Sep 11, 2019 12:16 am

### Re: 5% rule

The coefficients are taken into account when calculating the concentration of the reactants and the products. Once you have done that, I don't think you need to consider the coefficients again. For example, if you have calculated that there was x amount of product at equilibrium and y amount initially, it doesn't matter if the products have a coefficient in front of them since you already calculated the concentration by taking that into account.

Emily Burghart 1k
Posts: 50
Joined: Wed Sep 18, 2019 12:17 am

### Re: 5% rule

805394719 wrote:The coefficients are taken into account when calculating the concentration of the reactants and the products. Once you have done that, I don't think you need to consider the coefficients again. For example, if you have calculated that there was x amount of product at equilibrium and y amount initially, it doesn't matter if the products have a coefficient in front of them since you already calculated the concentration by taking that into account.

I agree with this individual. Because we have already calculated the concentration of the [R] and [P], there is no need to consider the coefficients when calculating the 5% rule.

All you have to do is calculate

$\frac{x}{initial concentration}*100$

and compare that number to 5%. You can tell from this equation that your x is not in any way modified by the presence of a coefficient.