what happens to the yield of hydrogen if the reaction is carried out at a higher pressure but at the same temperature

The yield of hydrogen decreases

Explanation:

The Haber process is exothermic. The equation of the Haber process is;

N2(g) + 3H2(g) > 2NH3(g)    ΔH = -ve

Now, if we maintain a constant temperature, the number of volumes will affect the yield of products as follows;

The higher the pressure the lesser yield of hydrogen because the increase in pressure shifts the equilibrium position towards the right hand side.

passing a magnet thought the

mixture , because iron gets attracted to magnet .

dynamic equilibrium is the answer.