What is the molar concentration of H atoms at equilibrium if the equilibrium concentration of H2 is 0.28 M? Express your answer to two significant figures and include the appropriate units.

0.56M

Explanation:

Molar concentration is defined as the ratio between moles of solute and volume in liters of solution.

In a 0.28M H₂ there are 0.28moles of H₂ per liter of solution.

Now, in 1 molecule of H₂ there are 2 atoms of H. Following this idea, in 0.28 moles of H₂ there are 0.28*2 = 0.56 moles of H atoms.

Thus, molar concentration of H atoms in a 0.28M H₂ is 0.56M