Not zero, first, or second?

[charlottesmith3f]

What happens if we have a problem in which the rate is multiplied by two but the concentration is multiplied by four?
Is there such thing as not a zero, first, or second order, but, maybe, a half-order reaction or something?

[GunvantChaudhari 2F]

Yes there is such a thing as a half order reaction. For examples of how a reaction mechanism would lead to a half order reaction, see examples 2 and 3 here: http://www.science.uwaterloo.ca/~cchieh/cact/c123/ratemech.html

[Matt Villanueva 3H]

If the rate doubles but the concentration quadrupled, then yes, the order with respect to that reactant would be a half order.

[Alex Yee - 4I]

Is there any limit to what the order of a reaction can be? Could you (theoretically) have a reaction of pi order or 2/7 order, or is it just whole numbers and their inverses?

[GregoryPolyakov_1H]

Do we need to be familiar with half order reactions?