Given is the ratio of conjugate base and conjugate acid of phosphoric acid. pH of a substance is the concentration of the hydrogen ions in its solution and higher this concentration lower is the value of pH.
pKa value is a measure of the strength of acid, it is the negative log of acid dissociation constant Ka.
The mass of water decomposed to produce 50 g oxygen has been 56.28 g. Thus, option D is correct.
The reaction for the decomposition of water has been:
From the balanced equation, 2 moles of water decomposes to form 1 moles of hydrogen and 1 mole of oxygen.
The mass of oxygen produced has been 50 g. The moles of oxygen has been given by:
The moles of oxygen has been:
The moles of oxygen produced has been 1.5625 mol.
The moles of hydrogen decomposed has been given from the balanced chemical equation as:
The moles of hydrogen decomposes has been 3.125 mol.
The mass of hydrogen decomposed has been given by:
The mass of water decomposed to produce 50 g oxygen has been 56.28 g. Thus, option D is correct.
For more information about moles produced, refer to the link: