Most probably the answer is 'In Liquid State'
The following are neutral salts: NANO3, BaBr2 AND Ba[OH]2.
Neutral salts are those salts that are formed when a strong base react with a strong acid. In those neutralization reactions, the base completely neutralize the acid to form a neutral salts.
It has a positive charge, 22-18= +4
<u>Answer:</u> The correct option is
<u>Explanation:</u>
A catalyst is defined as the chemical species that increases the reaction rate but does not participate in it and is left behind after the completion.
A homogeneous catalyst is one that is present in the same phase as the reactants and products.
A heterogeneous catalyst is one that is present in different phase as that of reactants and products.
For the given chemical reaction:

As all the reactants and products are in gaseous state so, the homogeneous catalyst must also be in the gaseous state only.
Hence, the correct option is 