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.

answer:

the reaction is type of combination reaction.

explanation:

on the product side, there are 2 molecules of bonded to fe   which means one atom of fe are combined two molecules of . so, balanced chemical equation becomes :

this reaction follows the reaction type of combination reaction. a combination reaction is defined as chemical reaction in which reactants combines together to form a single product.