The subscripts indicate the number of atoms of the element immediately before it.
Answer:
The spectator ions is:
and 
Explanation:
The equation of reaction between H₂ SO₄ and KOH is:

Rewriting this equation as ionic;
![[2H^{+} + SO^{2-}_4 + 2K^+ +2OH^- \to 2K^+ SO_4^{2-} + 2H_2O ]](https://tex.z-dn.net/?f=%5B2H%5E%7B%2B%7D%20%2B%20SO%5E%7B2-%7D_4%20%2B%202K%5E%2B%20%2B2OH%5E-%20%5Cto%202K%5E%2B%20%20SO_4%5E%7B2-%7D%20%2B%202H_2O%20%5D)
Spectators ions are ions present on both sides of the ionic equation by the same quantity but do not take part in the net reaction.
It would be an physical change ; if you melt butter the butter goes from a solid to a liquid so therefore the physical state is changed.
Yes, o-toluic acid is soluble in ether as ether is slightly polar and it is soluble in NaOH because it is likely to form soluble compounds with it.
Naphthalene is insoluble in NaOH.