What is defined as a fraction with equilibrium product concentrations in the numerator and equilibrium reactant concentrations in the denominator and each concentration raised to a power equal to the corresponding stoichiometric coefficient in the balanced chemical equation? select one:
a. mass action
b. equilibrium expression
c. reversibility expression
d. reaction expression
e. product quotient

B. Equilibrium expression

Explanation:

Imagine this example

aA  +  bB  ⇄  nAB

K = Equilibrium constant.

How do you calculate K

K = (AB)ⁿ / Bᵇ . Aᵃ

n+h→nh3

we must remember that nitrogen and hydrogen are both diatomic molecules in their standard gas form. this adjusts the equation to

n2+h2→nh3

now we need to adjust coefficients in order to balance the atoms on each side of the equation. currently we have 2 atoms of nitrogen and 2 atoms of hydrogen on the reactant side and 1 atom of nitrogen and 3 atoms of hydrogen on the product side.

we can balance the hydrogens by placing a coefficient of 2 in front of ammonia and a coefficient of 3 in front of the hydrogen.

n2+3h2→2nh3

this gives us 6 hydrogen on each side and coincidentally the nitrogens now equal 2 on each side.