Empirical And Molecular Formulas of A Substance From Its Percent Compositions
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Empirical And Molecular Formulas of A Substance From Its Percent Compositions Determine the empirical and molecular formulas for the following substances:
(a) Styrene with molar mass of 104 g/mol; carbon (C) percent composition is 92.3%; hydrogen (H) is 7.7% by mass.
(b) Caffeine with molar mass 195 g/mol; carbon (C) percent composition is 49.5%; hydrogen (H) is 5.15%; nitrogen (N) is 28.9%; oxygen (O) 16.5% by mass.
(c) Monosodium glutamate (MSG) with molar mass 169 g/mol; carbon (C) percent composition is 35.51%; hydrogen (H) is 4.77%; oxygen (O) is 37.85%; nitrogen (N) is 8.29%; sodium (Na) is 13.60%.

The strings: S7P2A22 (identity-chemical).

The math:
Pj Problem of Interest is of type identity (chemical). (a)Assume 100g mass of styrene:
So, moles of carbon = 92.3/12 = 7.7 moles
So, moles of hydrogen = 7.7/1 = 7.7 moles
So, mole ratio is 1:1
So empirical formula = CH
Mass from empirical formula = 12 + 1 =13
Given molar mass of styrene = 104 g/mol
So, molar mass is 8 times mass from empirical formula
So, Molecular formula = C8Hsub>8.

(b)Assume 100g mass of caffeine:
So, moles of carbon = 49.5/12 = 4.125 moles
So, moles of hydrogen = 5.15/1 = 5.15 moles
So, moles of nitrogen = 28.9/14 = 2.06
So, moles of oxygen = 16.5/16 = 1.03
So, mole ratios is 4:5:2:1
So, empirical formula = C4H5N2O
Mass from empirical formula = 48 + 5 + 28 + 16 = 97
Given molar mass of caffeine = 195 g/mol
So, molar mass is 2 times mass from empirical formula
So, Molecular formula = C8H10N4O2.

(c)

(b)Assume 100g mass of caffeine:
So, moles of carbon = 35.5/12 = 2.96 moles
So, moles of hydrogen = 4.77/1 = 4.77 moles
So, moles of oxygen = 37.85/16 = 2.37
So, moles of nitrogen = 8.29/14 = 0.59
So, moles of sodium = 13.6/23 = 0.59
So, mole ratios is 5:8:4:1:1
So, empirical formula = NaC5H8O4N
Mass from empirical formula = 23 + 60 + 8 + 64 + 14 = 169
Given molar mass of monosodium glutamate =169 g/mol
So, molar mass is equals mass from empirical formula
So, Molecular formula = NaC5H8O4N

Math The Universe is composed of matter and radiant energy. Matter is any kind of mass-energy that moves with velocities less than the velocity of light. Radiant energy is any kind of mass-energy that moves with the velocity of light.
Periodic Table
Composition And Structure Of Matter
How Matter Gets Composed
How Matter Gets Composed (2)
Molecular Structure Of Matter
Molecular Shapes: Bond Length, Bond Angle
Molecular Shapes: Valence Shell Electron Pair Repulsion
Molecular Shapes: Orbital Hybridization
Molecular Shapes: Sigma Bonds Pi Bonds
Molecular Shapes: Non ABn Molecules
Molecular Orbital Theory
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