It is a covalent bond. Whenever a compound uses such suffixes like mono, di, tri, tetra, and so on, it is a covalent compound- thus having covalent bonds.
Answer:7 atom of carbon+5atom of hydrogen +3atom of nitrogen +6 atom of oxygen =21
Moles of gas = 0.369
<h3>Further explanation</h3>
Given
P = 2 atm
V = 5.3 L
T = 350 L
Required
moles of gas
Solution
Ideal gas Law

Avogadro's law : at the same temperature and pressure, the ratio of gas volume will be equal to the ratio of gas moles
moles of O₂ = 45% x 0.369 = 0.166
moles of Ar = 12% x 0.369 = 0.044
moles of N = 43% x 0.369 = 0.159