Question

How long would it take the same amount of gaseous I2to effuse from the same container under identical conditions? Express your answer using two significant figures.

a) It depends on temperature
b) Twice the time for O_2
​c) Four × the time for H_2
​d) The same time as O_2
​

Answer 1

Iodine gas effuses at half the rate of oxygen, thus, it takes twice the time for the same amount of iodine gas to effuse from a container compared to oxygen under identical conditions.

Step-by-step explanation:

The question asks about the rate at which gaseous Iodine (I2) effuses compared to Oxygen (O2) and Hydrogen (H2). To answer this, we use Graham's Law of Effusion which states that the rate of effusion of a gas is inversely proportional to the square root of its molar mass (MM). The ratio of effusion rates of two gases can be described by the equation:

Rate1 / Rate2 = √(MM2 / MM1)

Given that the molar mass of H2 is approximately 2 g/mol and that of I2 is approximately 254 g/mol, we can calculate how much slower iodine effuses relative to hydrogen:

RateI2 / RateH2 = √(2 / 254) <is approximately> 1/8

This means iodine effuses 8 times slower than hydrogen. If hydrogen effuses four times as rapidly as oxygen, it implies that oxygen effuses two times faster than iodine. Therefore, iodine will effuse at half the rate of oxygen, taking twice the time of oxygen to effuse from the same container under identical conditions.