The reaction
2 so2(g) + o2(g)< --> 2 so3(g)
has an equilibrium expression. the mass action expression
forconcentration of oxygen has an exponent of

The mass action expression  for concentration of oxygen has an exponent of one.

Explanation:

2 SO₂(g) + O₂(g) ⇄ 2 SO₃(g)

This is the expression for Kc:

Kc = [SO₃]² / [O₂] . [SO₂]²

The mass action expression has a totally relation with stoichiometry.

for step 7 table c on the lab "newtons law of action"   the average time it took the car to travel .25 meters   was 1.92 seconds.

the average time it took the car to travel 0.50 meters was 2.61 seconds

hope this : )