HgO(s) Hg(l) + O2(g)Consider the unbalanced equation above. A sample of impure mercury(II) oxide is heated and the HgO decomposed completely. If 580. mL of O2 is collected by displacement of water at a barometric pressure of 790.0 mm Hg and 25.0°C, what mass of HgO was originally present? The vapor pressure of water is 23.8 mm Hg at 25.0°C. Use molar masses with at least as many significant figures as the data given.