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.

one negative thing it that it can kill water animals. another negative thing is it can cause the destruction of ecosystem. one way water pollution can be reduced is to conserve energy.