Hello.

I guess you're talking about order of reaction. If so, and If those are experimental values, then yes. It's frequent to observe orders of 0.5 or 1.5 for chain reactions in thermal pyrolysis which are also refered in kinetics textbooks, as for example the C2H6 or CH3CHO pyrolysis. Also if, let's say A, can be broken in two parts (as Cl2 for example), the order to A can be 0.5.

Again, if your values are experimental, there will always be variability and error associated with them, so they are what they are.

Cheers

As Mário Silva indicated, experiments may show a non-integer behaviour of the reaction order. This occurs if your equations are only sum balances and not the full microscopic mechanism (which is the case in almost all balances with more than three participants). So, if you want to communicate this externally you should always talk about a "pseudo order" of the overall reaction.

An elementary reaction has an integer order. In this case, the number of educts is one or two (because the probability for three molecules to react is very small). Furthermore, the educts are whole molecules. If the chemical reaction is not an elementary reaction, the order can be a non-integer number.

However, the number of elements is constant (except for nuclear reactions). Hence, coefficients nA=0.7 and nB=1.41 seem unlikely (even for a non-elementary reaction).

What do you mean by "reaction coefficient". Each coefficient in the kinetic equation can be non-integer number. Whether there is a reversible reaction or not it has no effect here. The mechanism of the chemical reaction is decisive. If you mean stoichiometric coefficients, they can also be non-integer numbers. Regards,

Dear;

There is no fixed relation between reaction orders and stoichiometric coefficients.

Here you are taking about equilibrium constant and not about reaction orders!?

Equilibrium constants in terms of activity coefficients correlating inter-molecular ( reactants & products) interactions expressed as function of activities and stoichiometric coefficients .You must care that reactions between reacting materials involved are based on mole basis and the Ka is strictly defined via activity coefficient of both products and reactants and their stoichiometric coefficients.

Any experimentally obtained results for Ka not obeying the above mentioned expression of Ka are attributed to both deviation from ideal behavior of the reaction mixture and to the experimental errors.

Exponents in the kinetic equation in the form of a power monomial (an irreversible reaction) or a power binomial (a reversible reaction) may be, but often are not equal to the stoichiometric coefficients. The mechanism of a given chemical reaction determines this. ........ The question is not clear, so we are really guessing what the questioner meant. Regards,