What is the empirical and molecular formula of the compound?

What is the empirical formula of this compound?help me please...?

• Organic compound Z consists of elementary constituent compound of carbon, hydrogen and oxygen. When 0.75 g sample of the compound is burned completely, 1.10 g of CO2 and 0.45 g H2O are formed. The mass of 1.505 x 1023 molecules of Z is 15.02 g. 1) Calculate the empirical formula of compound. 2) What is the molecular formula of Z? please break it down for me...appreciate it so much! p/s; i`m not so good in english, hope u can understand,tq.

• Answer:

  mass of C in 1.10g of CO2 = 1.10 x 12 / 44 = .300 g of C mass of H in .45 g of H2O = .45 x 2 / 18 = .05 g of H mass of C+ H = .350 g so mass of O = .75 -.35 = .40g moles of C = .300 / 12 = 0.025 moles moles of H = .05 mole sof O = .40 / 16= .025 moles molar ratio of C : H : O = .025 : .05: .025 or 1 : 2:1 empirical formula is CH2O empirical mass = 12+2+16 = 30 g 1.505 x 10 * 10^23 molecules have mass of 15.02 g so 1 mole or 6.02 x 10 ^23 molecules have mass of 15.05 x 6.02 / 1.505 = 60.2 g / mole there are 2 empirical units in 1 mole so the molecular formula is C2H4O2 ..