Answer:
0.02 tons of NO produced when 4 tons of coal is burned
Explanation:
From the given,
Chemical formula of coal = 
Molecular mass of coal = 
Let’s calculate the mass of nitrogen in coal


Amount of coal burnt = 4tons
Amount of NO produced by burning 4tons = 
This nitrogen is converted into NO by reacting with atmospheric oxygen.
The given equilibrium reaction is,

The given reaction is exothermic. So, heat energy will be a product. Therefore, decreasing the temperature (heat energy) would lead to the formation of more products as when the amount of energy which is a product is reduced, there is more room for the products to form.
Increasing the pressure would shift the equilibrium towards that side which has least number of moles of the gaseous substance. Hence, here increasing the pressure would lead to the formation of more products by shifting the equilibrium towards the right side.
Decreasing the volume would make the equilibrium shift towards the least number of moles of the gaseous substance. So, here in this equilibrium decreasing the volume would lead to the formation of more products.