Question

A) Find the gas speed of ammonia at 25.0 degrees Celsius. ______________

b) What is the rate of effusion of ammonia compared to silicon tetra bromide gas as the same temperature? __________________

Answer 1

a. 661.23 m/s

b. the rate of effusion of Ammonia = 4.5 faster than Silicon tetra bromide

Further explanation

Given

T = 25 + 273 = 298 K

Required

a. the gas speed

b. The rate of effusion comparison

Solution

a.

Average velocities of gases can be expressed as root-mean-square averages. (V rms)

`\large {\boxed {\bold {v_ {rms} = \sqrt {\frac {3RT} {Mm}}}}`

R = gas constant, T = temperature, Mm = molar mass of the gas particles

From the question

R = 8,314 J / mol K

T = temperature

Mm = molar mass, kg / mol

Molar mass of Ammonia = 17 g/mol = 0.017 kg/mol

`\tt v=\sqrt{(3* 8.314* 298)/(0.017) }=661.23~m/s`

b. the effusion rates of two gases = the square root of the inverse of their molar masses:

`\rm (r_1)/(r_2)=\sqrt{(M_2)/(M_1) }`

M₁ = molar mass Ammonia NH₃= 17

M₂ = molar mass Silicon tetra bromide SiBr₄= 348

`\rm (r_1)/(r_2)=\sqrt{(348)/(17) }=4.5`

the rate of effusion of Ammonia = 4.5 faster than Silicon tetra bromide