Acid strength of nonmetal hydrides Across a period, acid strength increases, so the electronegativity of the nonmetal element determines this trend. Down a group, acid strength increases because the atom gets bigger and so it is easier to remove the H. This trend is only seen in non aqueous solution since the water leveling effect makes the hydronium ion the strongest acid (the acid with react with water to form water autoionization products). Acid Strength of oxoacids All oxoacids have the acidic H atom bonded to an O atom. For oxoacids with the same number of O atoms, acid strength increases with the electronegativity of the central atom. For oxoacids with different numbers of O atoms, acid strength increases with the number of O atoms (the more O atoms the stronger the acid). Rank the following acids from weakest to strongest acids: A. HFO2, HClO2, HBrO2, B. HIO, HIO2, HIO3, HIO4 C. the following acids are dissolved in a nonaqueous solvent such as acetone: HF, HCl, HBr, HI