Answer:
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
