An unknown gas effuses at one half the speed of oxygen. what is the molar mass of the unknown? it is either hbr or hi. which gas is it?

HI.

Explanation:

Rate of effusion ∝ 1/√molar mass.

∵ Rate of effusion of unknown gas = 1/2 (Rate of effusion of O₂)

∴ (Rate of effusion of O₂) / (Rate of effusion of unknown gas) = 2.

Molar mass of O₂ = 32.0 g/mol.

∵ (Rate of effusion of O₂) / (Rate of effusion of unknown gas) = (√molar mass of unknown gas) / (√molar mass of O₂).

∴  2.0 = (√molar mass of unknown gas) / √32.0.

( √molar mass of unknown gas) = 2.0 x √32.0

By squaring the both sides:

∴ molar mass of unknown gas = (2.0 x √32.0)² = 128 g/mol.

∴ The molar mass of sulfur dioxide = 80.91 g/mol and the molar mass of HI = 127.911 g/mol.

So, the unknown gas is HI.

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.

i think its 100

i hope this !