H3bo3, hcno, hcn, hf which of them has the strongest acid

I believe it's HF

Explanation:

 A. HF    Explanation:(Ka for HF is 7.2X10^-4)

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.

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.