Nitrogen and oxygen form an extensive series of oxides with the general formula NxOy. What is the empirical formula for an oxide that contains 30.44% by mass nitrogen?

Explanation:

Given, mass percentage of Nitrogen is 30.44

So, mass percentage of Oxygen is 100 - 30.44 = 69.56

Calculation:-

Element   Mass       Atomic      Number of      Simple molar       Simple whole

                percent    mass      moles             ratio                   number ratio

Nitrogen30.44       14       2.17          2.17/2.17 = 1           1

Oxygen69.56       16       4.34          4.34/2.17 = 2           2

So, Empirical formula =

o conteúdo de calor de um sistema é igual à entalpia apenas para um sistema que é constante

the answer is d.) potassium