Hello. I just started a first year chemistry course after switching to the sciences from the arts, and wanted to double-check some equations with you because this is a little new to me. I'm good with the qualitative stuff, but the quantitative parts come a little harder. Q1: A sheet of metal is 93.3 mm wide and 40.6 mm long. If it weighs 4.877 g and the density of the metal is 1.74 g/cm3, what is the thickness of the sheet (in mm)? My answer: 4.877g / 1.74g/cm^3 = 2.80cm^3 93.3mm x 40.6mm = 3780mm (3 sig figures) 2.80cm^3 / 3780mm = 0.740mm 93.3mm x 40.6mm x 0.740mm = 2.80cm^3 Thus, the sheet is 0.740mm thick. Q2: If PV = [gR(T+273.15)]/M, solve for M when P = 334, V = 0.350, g = 0.274, R = 62.37, and T = 39. My answer: PV = [gR(T+273.15)] / M (334)(0.350) = (0.274) (62.37) (312.15) / M 116 = 5330 (3 sig figures) / M 116 / 5330 = M 0.0217 = M Q3: An ore contains 42.3 % of the mineral ilmenite, FeTiO3, which is a source of the element Ti. How much ore must be processed in order to obtain 41.0 kg of Ti? Molar masses Fe = 55.85g Ti = 2004.4g O = 16.00g x 3 = 48.00g total = 308.2g 308.2g / 204.4g = 1.50 41.0kg x 1.50 = 61.5kg 100 / 42.3 = 2.36 61.5 x 2.36 = 145 kg of ore are needed to obtain 41.0kg of thallium. Thank you all in advance. M.