3. In which reaction is the volume of the products equal to the volume of the reactants?
A 2H2(g) + O2(g) → 2H2O(g)
B 3H2(g) + N2(g) → 2NH3(g)
C N2(g) + O2(g) → 2NO(g)
D 2502(g) + O2(g) → 2503(g)

c. because step up transformer steps up the input voltage i.e increases the input voltage  

the number of turns are greater on the secondary side of step up transformer  

transformer does not handle dc current

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.