Can someone help me ASAP THIS IS IS A IMPORTANT GRADE

Water ionizes by the equation h2o(l)⇌h+(aq)+oh−(aq) the extent of the reaction is small in pure water and dilute aqueous solutions. this reaction creates the following relationship between [h+] and [oh−]: kw=[h+][oh−] keep in mind that, like all equilibrium constants, the value of kw changes with temperature.

Match the formula for the following compound:   magnesium sulfate heptahydratemgs·7h2omg2so4·7h2omg(s o4)2·7h2omgso4·7h2o

Balance the following reaction. as2s3 + 9o2 → 2as2o3 + so2