Question

A sample of a compound contains 7.89 g potassium, 2.42 g carbon, and 9.69 g oxygen. What is the empirical and molecular formulas of this compound, which has a molar mass of 198.22 g/mol?

Answer 1

The empirical formula of the compound is KCO and the molecular formula is K2C2O2.

Step-by-step explanation:

To find the empirical formula of a compound, we need to determine the ratio of atoms in the compound. First, we calculate the moles of each element by dividing the mass of each element by its molar mass.

Next, we divide the number of moles of each element by the smallest number of moles to obtain the simplest whole-number ratio of atoms. In this case, the ratio of potassium:carbon:oxygen is 1:1:1. Therefore, the empirical formula of the compound is KCO.

To determine the molecular formula, we need to know the molar mass of the compound. The problem states that the molar mass is 198.22 g/mol. The molar mass of the empirical formula (KCO) is 98.18 g/mol.

By dividing the molar mass of the compound by the molar mass of the empirical formula, we can determine the number of empirical formula units in each molecule. In this case, the molecular formula is K2C2O2.