What is the molecular formula of a compound that has the empirical formula CH and a molar mass of 78.1 g/mol?

Question

Quizplus · Accepted Answer

The empirical formula CH means that there is 1 carbon atom and 1 hydrogen atom in the compound. The molar mass of 78.1 g/mol tells us the mass of one mole of the compound, which is equal to the sum of the masses of all the atoms in the compound. To calculate the molecular formula, we need to determine the number of atoms of each element in one molecule of the compound. Let's call the subscripts for carbon and hydrogen in the molecular formula x and y, respectively. The mass of one mole of the compound can be calculated as: Molar mass = (12.01 x) + (1.01 y) We also know that the empirical formula mass is: Empirical formula mass = 12.01 + 1.01 = 13.02 The molecular formula mass is a multiple of the empirical formula mass: Molecular formula mass = n x empirical formula mass where n is an integer. We can use these equations to solve for x and y: Molecular formula mass = (12.01 x) + (1.01 y) = n x empirical formula mass = n x 13.02 78.1 = 12.01x + 1.01y n = 78.1 / 13.02 = 6 12.01x + 1.01y = 78.1 We can try different values of x and y that satisfy this equation and the constraint that they are integers. One possible set of values is x = 6 and y = 10. Therefore, the molecular formula of the compound is C6H10, which is equivalent to C₆H₆ in Hill notation.

What Is the Molecular Formula of a Compound That Has