If the concentration of water inside a cell is higher than the concentration of water outside a cell, osmosis will take place, as water will move from an area of low solute concentration inside the cell to higher solute concentration, outside the cell.
The answer is 2H2 + O2----> 2H2O
This is because oxygen (2.8.6) requires two electrons on its valence shell to attain stable configuration (2.8.8). Hydrogen (1) on the other hand requires one electron on its valence shell to attain stable configuration (2). Therefore in a covalent bond, it requires two hydrogen and one oxygen to share electrons and achieve stable configuration.
