5% Rule

[Seohyun Park 1L]

Does the 5% Rule for approximation only apply to acid/base reactions in water? Can we use the approximation technique for small K values for equilibrium problems not involving acid/base?

[Tarika Gujral 1K]

The 5% approximation technique can be used for any K calculation, provided

K < 10-3 — Very little product formed, R-x = R
K > 103 — Very little reactant remaining, P+x = P

[Irene Zhou 1E]

The 5% ionization approximation can be applied to any K calculation as long as K is less that 10^-3

[juliasloan_4g]

the 5 percent rule can be used in any calculation of K

[sophiebillings1E]

But if you do disregard x make sure to double check that it is under 5% because if not the solution is incorrect.

[Jasmine Chow 1F]

you can use the 5% rule for a K value that is less than 10^-3 for acids and bases or equilibrium concentrations and pressures.