You can use the formula M1 x V1 = M2 x V2 where M1 is the molarity of the first substance and V1 is the volume of the substance. M2 is the molarity of the 2nd substance and V2 is the volume of the substance
if substance 1 is HCl and 2 is KOH we can set up the following equation
x moles / liter (unknown) x .02 liters = .5 moles/ liter x .032 liters
No they form nitrogen oxide which can be poisonous to some species but depending on the amount of nitrogen it can be harmful to everything living. Such as if you put it with a plant that had low nitrogen levels then there would be no carbon dioxide to filter.
