Question

A 100.0-mL flask contains 0.193 g of a volatile oxide of nitrogen. The pressure in the flask is 760 mmHg at 17°C. Is the gas NO, NO2, or N2O5?

Answer 1

Answer:

$NO_2$

Explanation:

Considering,  

$n=\frac{m}{M}$

Using ideal gas equation as:

$PV=\frac{m}{M}RT$

where,  

P is the pressure  = 760 mmHg

V is the volume  = 100.0 mL = 0.1 L

m is the mass of the gas  = 0.193 g

M is the molar mass of the gas  = ?

Temperature = 17 °C

The conversion of T( °C) to T(K) is shown below:

T(K) = T( °C) + 273.15  

So,  

T = (17 + 273.15) K = 290.15 K

R is Gas constant having value = 62.36367 L. mmHg/K. mol

Applying the values as:-

$760\times 0.1=\frac{0.193}{M}\times 62.36367\times 290.15$

M = 45.95 g/mol

This mass corresponds to $NO_2$. Hence, the gas must be $NO_2$.