Can you help me with this AP Chem problem? thanks

Question

Hydrogen azide decompose on heating by the following unbalanced equation

HN3=N2(g)+H2(g)

If 3.0 atm of pure HN3 is decomposed initally, what is the final total pressure of the container?
What are the partial pressures of the hydrogen and nitrogen gas?

Answer 1

2HN3 = 3N2 + H2

2 moles of HN3 results in 4 moles of decomposed gases. 3.0 atm of HN3 will result in (4/2)* 3 = 6atm of pressure.