Need help with Chemical equilibrium...?

Question

1.) Identify which of the following are examples of chemical
equilibrium:

a.) 2NO2 <==> N2O4

b.) 2H2O <==> 2H2 + O2

c.) N2 + 3H2 <==> 2NH3 + heat

d.) H2 + I2 <==> 2HI

Answer 1

not a. the product is not a possible compound.

b. yes, though very little water is decomposing, and hydrogen gas is very reactive. little forward arrow - big reversing arrow.

c. yes, this is one of the classic equilibrium reactions.

d . yes, but this is the opposite of b. big forward arrow - little reversing arrow.

Answer 2

first one isn't equilibrum example its an example of producing N2O4 by adding more O2 with NO2.
Other rest three equations r equilibrium example....coz all r forward n reverse reaction.