y CollegeCHEM 1020Spring18BARKER Activities and Due Dates Ch

y College-CHEM 1020-Spring18-BARKER Activities and Due Dates Chp 6 28/2018 10:01 AM 0.2/5 PrintCalculatorPeriodic Table ion 3 of 24 Sapling Learning What is the empirical formula of a compound composed of 3.25% hydrogen (H), 19.36% carbon (C), and 77.39% oxygen (O) by mass? HCO Insert subscripts as needed. E O Previous Check Answer 0 Next Hint contact us about us careers privacy policy torms of use

Solution

consider 100 g of compound is present, then the percentage is converted to grams

then the compound contain

3.25 g of hydrogen

19.36 g of carbon

77.39 g of oxygen

in next step conver the mass it to corresponding moles

molecular weight of hydrogen = 1.008 g/mol

then moles for 3.25 g of hydrogen is

3.25 g/1.008 g = 3.224 moles

molecular weight of carbon 12.0107 g / mol

then moles for 19.36 g of carbon is

19.36 g/12.0107 g = 1.611 moles

molecular weight for oxygen is 16 g / mol

then moles for 77.39 g of oxygen is

77.39 g/ 16 = 4.83 moles

in next step divide each moles value with least moles value, in above the least mole value is 1.611 moles for carbon

H = 3.224 / 1.611 = 2.001

C = 1.611 / 1.611 = 1.000

O = 4.83 / 1.611 = 3.00

therefore emprical formula is

CH₂O₃