Answer: For every one mole of Ca used in this reaction, two mols of H20 are used, one mole of Ca(OH)2 is formed, and one mole of H2 is formed.
Explanation: Once the equation is balanced, you can get the ratio from the coefficients. If you are looking at the ratio of Ca to H2O, the ratio is 1:2; Ca to H2 1:1.
