Determine the moles of oxygen gas (O2) needed to completely react with 1.975 moles of hydrogen gas (H2). Final answers should be reported with the correct number of significant digits. H2 (g) + O2 (g) ⟶ H2O (g)

0.9875 moles of O₂

Explanation:

The reaction for production of water is:

2H₂ + O₂ → 2H₂O

By stoichiometry, 2 moles of hydrogen need 1 mol of oxygen to react.

Then, we can make the following rule of three:

If 2 moles of H₂ need 1 mol of O₂ to react

Then, 1.975 moles of H₂ will need ( 1.975 . 1) /2 = 0.9875 moles of O₂

definition

                    entropy is a measure of the randomness or the extent of disorder of a chemical process.

                      enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.

measurement units:

                        entropy is measured in joule per kelvin (jk⁻¹)   whereas enthalpy is measured in joule per mole (jmol⁻¹)

requirements:

                            entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.

                              in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.