Why are molecular covalent compounds insoluble in water?

Hope this will help

Explanation Covalent bonds are insoluble in water (H2O) , but covalent compounds are. This is because some organic compounds (covalent) contain the polar −OH group which can bond to a hydrogen ion to form water.

the equation that correctly represent the reaction for formation of ammonia is

n2+ 3h2 → 2nh3 (answer d)

1 mole of nitrogen gas (n2) react with 3 moles of hydrogen gas (h2) to form 2 moles of ammonia ( nh3). this is in a process known as haber process were iron is used as a catalyst and reaction take place that a higher temperature and pressure. the process is exothermic hence energy is released.