A 1.0 mol sample of which of the following compounds has the greatest mass? A. NO
B. NO2
C. N2O
D. N2O5

(D) is the correct option.

Explanation:

Molar mass of NO = (14+16) g/mol = 30 g/mol

Molar mass of NO₂ = (14+16×2) g/mol = 46 g/mol

Molar mass of N₂O = (14×2+16) g/mol = 44 g/mol

Molar mass of N₂O₅ = (14×2+16×5) g/mol = 108 g/mol

Number of moles = mass/molar mass

mass = n × M, M = molar mass

n = 1 mol in each case

Higher the molar mass, greater is the mass of the compound. The molar mass of N₂O₅ is greatest of all other cases. It will have greatest mass.

the answer is definitely c.

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.