Answer:
N2O5
Step-by-step explanation:
First, you need to find the number of moles of each element in the compound. The molar mass of nitrogen is 14 g/mol and the molar mass of oxygen is 16 g/mol. So, the number of moles of nitrogen is 76 g / 14 g/mol = 5.43 mol and the number of moles of oxygen is 80 g / 16 g/mol = 5 mol.
Next, you need to find the simplest whole-number ratio between the number of moles of nitrogen and oxygen. This can be done by dividing both numbers by the smallest number of moles. So, the ratio is 5.43 mol / 5 mol = 1.09 : 1.
Since this ratio is close to 1:1, we can assume that the empirical formula of the compound is NO. However, since the molecular formula must be a whole-number multiple of the empirical formula, we need to multiply both subscripts by 2 to get N2O2.
Finally, we need to check if this molecular formula matches the given mass ratio. The molar mass of N2O2 is (2 * 14 g/mol) + (2 * 16 g/mol) = 60 g/mol. So, if we have 5.43 mol of N2O2, its mass would be 5.43 mol * 60 g/mol = 326 g. This does not match the given mass ratio.
Therefore, we need to try a different multiple of the empirical formula. If we multiply both subscripts by 5 instead of 2, we get N2O5. The molar mass of N2O5 is (2 * 14 g/mol) + (5 * 16 g/mol) = 108 g/mol. So, if we have 5.43 mol of N2O5, its mass would be 5.43 mol * 108 g/mol = 586 g. This matches the given mass ratio.
So, the correct answer is D. N2O5.