Single Choice

A gas diffuse $$\dfrac{1}{5}$$ times as fast as hydrogen. Its molecular weight is:

A$$50$$
Correct Answer
B$$25$$
C$$25\sqrt {2}$$
D$$50\sqrt {2}$$

Solution

Let,
$$R_{H_2}$$ be $$x$$
$$R_{G}$$ be $$\dfrac{1}{5}x$$
applying Graham's law of diffusion
$$\dfrac{R_{H_2}}{R_G}=\sqrt{\dfrac{M_G}{M_{H_2}}}$$
Where $$R_G$$ &$$M_G$$ represents the rate of diffusion and molecular mass of the gas.
Putting the values in the above equation
$$\dfrac{x}{\dfrac{x}{5}}=\sqrt{\dfrac{M_G}{2}}$$
$$5=\sqrt{\dfrac{M_G}{2}}$$
Squaring both sides
$$5^2=\dfrac{M_G}{2}$$
$$M_G=25\times 2=50$$


SIMILAR QUESTIONS

States of Matter - Gas and Liquid

According to Graham's law, at a given temperature the ratio of the rates of diffusion $$\dfrac {r_A}{r_B}$$ of gases $$A$$ and $$B$$ is given by: (where $$p$$ and $$M$$ are pressures and molecular weights of gases $$A$$ and $$B$$ respectively)

States of Matter - Gas and Liquid

Define Graham’s law of diffusion. Give its mathematical formulation.

States of Matter - Gas and Liquid

On which factors will the rate of diffusion of a gas depend?

States of Matter - Gas and Liquid

The gases $$A$$ and $$B$$ are kept in two cylinders and allowed to diffuse through a small hole. If the time taken by the gas $$A$$ is four times the time taken by gas $$B$$ for diffusion of equal volume of gas under similar conditions of temperature and pressure, what will be the ratio of their molecular weights?

States of Matter - Gas and Liquid

An open flask containing air is heated from 300 K to 500 K . What percentage of air will be escaped to the atmosphere, if pressure is keeping constant?

States of Matter - Gas and Liquid

According to Graham's law, at a given temperature the ratio of the rates of diffusion $$\dfrac {r_A}{r_B}$$ of gases $$A$$ and $$B$$ is given by: (where $$p$$ and $$M$$ are pressures and molecular weights of gases $$A$$ and $$B$$ respectively)

States of Matter - Gas and Liquid

If rate of diffusion of $$A$$ is 5 times that of $$B$$, what will be the density ratio of $$A$$ and $$B$$?

States of Matter - Gas and Liquid

If $$4\ g$$ of oxygen diffuse through a very narrow hole, how much hydrogen would have diffused under identical conditions?

States of Matter - Gas and Liquid

If some moles of $$O_2$$ diffuse in $$18$$ sec and same moles of an unknown gas diffuse in $$45$$ sec then what is the molecular weight of the unknown gas?

States of Matter - Gas and Liquid

Rate of diffusion of a gas is

Contact Details