Final answer:
To calculate the molecular formula of a gas, we need to know the molar mass and empirical formula. Using the ideal gas law equation, we can determine the number of moles of the gas. Then, by dividing the number of atoms of each element by the smallest number of atoms present, we can find the empirical formula. Finally, the molecular formula can be calculated by dividing the molar mass of the compound by the molar mass of the empirical formula.
Step-by-step explanation:
In order to calculate the molecular formula of a gas, we need to know the molar mass and empirical formula of the gas. The molar mass can be determined by using the ideal gas law equation, PV = nRT, where P is pressure, V is volume, n is the number of moles, R is the gas constant, and T is temperature. By rearranging the equation, we can solve for n, which represents the number of moles of the gas.
Once we have the number of moles, we can determine the empirical formula of the gas by dividing the number of atoms of each element by the smallest number of atoms present. The molecular formula can then be calculated by dividing the molar mass of the compound by the molar mass of the empirical formula.
In this specific case, we are given that the gas contains 30.4% nitrogen. We are also given that 4.0 g of the gas occupies a volume of 0.974 L at STP (Standard Temperature and Pressure). With this information, we can calculate the number of moles of the gas, determine the empirical formula, and then calculate the molecular formula.