Verified Answer :

According the Graham's Law of effusion, if we let M₁ and R₁ be the mass and effusion rate of NH₃ and M₂ and R₂ be the mass and effusion rate of O₂, then: 

R₂/R₁ = √(M₁/M₂). 

Since M₁ = 14.01 + 31.01 = 17.04 and M₂ = 16 2 = 32, we see that: 

R₂/R₁ = √(17.04/32) = 0.73 
==> R₂ = 0.73 * R₁. 

Thus, O₂ effuses at 73% the speed that NH₃ does

Answer : The rate of effusion of ammonia gas is 1.37 times of rate of effusion of oxygen gas.

Solution :

According to the Graham's law, the rate of effusion of gas is inversely proportional to the square root of the molar mass of gas.

\(R\propto \sqrt{\frac{1}{M}}\)

or,

\(\frac{R_1}{R_2}=\sqrt{\frac{M_2}{M_1}}\)

where,

\(R_1\) = rate of effusion of ammonia gas

\(R_2\) = rate of effusion of oxygen gas

\(M_1\) = molar mass of ammonia gas  = 17 g/mole

\(M_2\) = molar mass of oxygen gas  = 32 g/mole

Now put all the given values in the above formula, we get :

\(\frac{R_1}{R_2}=\sqrt{\frac{32g/mole}{17g/mole}}\)

\(\frac{R_1}{R_2}=1.37\)

\(R_1=1.37\times R_2\)

Therefore, from this we conclude that, the rate of effusion of ammonia gas is 1.37 times of rate of effusion of oxygen gas.