Happy Birthday RFK (1925) Mastering Chemistry

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Happy Birthday RFK (1925) Mastering Chemistry New assignment will be posted later today Due Sunday by 11:59PM

Molecular Formulae: The Next Step What is the empirical formula of: C6H9N3 ratio = 3 to 1 C2H3N What are the molar masses of the molecular and empirical formulae? C6H9N3 = 123.1590 g/mol ratio = 3 to 1 C2H3N = 41.0530 g/mol

Molecular Formulae: The Next Step Molecular formula and empirical formula will always have the same ratio as the molecular mass and the empirical mass! If a compound has a molar mass of 78.1150 g/mol and an empirical formula of CH, what is the molecular formula? empirical mass = 13.0092 g/mol mass ratio = 6 to 1 formula ratio = 6 to 1 6(CH)  C6H6 molecular formula = C6H6

Molecular Formulae: The Next Step Caffeine is my life blood! Give the empirical and molecular formulae based on: 40.09g C, 4.172g H, 23.41g N, and 13.37g O. The molar mass of caffeine is 194.19 g/mol C4H5N2O

Molecular Formulae: The Next Step Caffeine is my life blood! Give the empirical and molecular formulae based on: 40.09g C, 4.172g H, 23.41g N, and 13.37g O. The molar mass of caffeine is 194.19 g/mol C4H5N2O C4H5N2O = 97.0975 g/mol mass ratio = 2 to 1 formula ratio = 2 to 1 2(C4H5N2O)  C8H10N4O2 molecular formula = C8H10N4O2

Molecular Formulae: The Next Step Give the empirical and molecular formulae for a compound based on: 6.85g C, 0.432g H, 3.41g O, and 11.4g Br. The molar mass of the compound is 929.88 g/mol ~ 4 mol C ~ 3 mol H ~ 1.5 mol O 1 mol Br C8H6O3Br2

Molecular Formulae: The Next Step Give the empirical and molecular formulae for a compound based on: 6.85g C, 0.432g H, 3.41g O, and 11.4g Br. The molar mass of the compound is 929.88 g/mol C8H6O3Br2 = 309.96 g/mol C8H6O3Br2 mass ratio = 3 to 1 formula ratio = 3 to 1 3(C8H6O3Br2)  C24H18O9Br6 molecular formula = C24H18O9Br6

You analyze a 73.8241g sample of 18-crown-6 (a specific crown either) and find that there are 40.2489g of carbon and 26.8055g of oxygen in the sample with the rest being hydrogen. a) What are the percents of carbon and oxygen in the sample of 18-crown-6? What is the percent of hydrogen in 18-crown-6? What is the empirical formula of 18-crown-6? 18-crown-6 has a molar mass of 264.32 g/mol. What is the molecular formula?