[Harps75]

Hi i have a question that i am really stuck on and wondered if anyone could help me out there.
Here goes,

'D' has a composition mass of Na = 27.1%, N=16.5%, 0=56.4%.
On heating 3.4g of 'D' it was broken down into Sodium Nitrite (NaNO2) and Oxygen. Showing your workings suggest an identity for 'D' and calculate the volume at room temperature and pressure of Oxygen that was formed. Include in the equation for the reaction in your answer
Thanks

[cth]

You're looking for a compound with a formula Na_xN_yO_z.

x, y and z are numbers in mole, but the given composition is in mass. So, you simply need to convert it to mole composition.