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?

Respuesta :

Answer:

[tex]NO_2[/tex]

Explanation:

Considering,  

[tex]n=\frac{m}{M}[/tex]

Using ideal gas equation as:

[tex]PV=\frac{m}{M}RT[/tex]

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:-

[tex]760\times 0.1=\frac{0.193}{M}\times 62.36367\times 290.15[/tex]

M = 45.95 g/mol

This mass corresponds to [tex]NO_2[/tex]. Hence, the gas must be [tex]NO_2[/tex].

Lanuel

A gas with a molar mass of 47.42 g/mol is likely to be [tex]NO_2[/tex]  because the molar mass of [tex]NO_2[/tex]  is 46 g/mol.

Given the following data:

  • Mass = 0.193 g
  • Volume = 100-mL.
  • Temperature = 17.0°C
  • Pressure = 760 mmHg
  • Ideal gas constant, R = 0.0821L⋅atm/mol⋅K

Conversion:

Volume = 100-mL to Liters = 0.100 L.

Temperature = 17.0°C to Kelvin = 290 K.

Pressure = 736 mmHg to atm = 0.97 atm.

To determine the unknown gas, we would use the ideal gas law equation;

[tex]PV = \frac{M}{MM} RT[/tex]

Where;

  • P is the pressure.
  • V is the volume.
  • M is the mass of substance.
  • MM is the molar mass of a substance.
  • R is the ideal gas constant.
  • T is the temperature.

Making MM the subject of formula, we have:

[tex]MM = \frac{MRT}{PV} \\\\MM = \frac{0.193(0.0821)(290)}{0.97(0.100)}\\\\MM = \frac{4.60}{0.097}[/tex]

Molar mass, MM = 47.42 g/mol.

MM of [tex]NO_2[/tex] = 14 + 32 = 46 g/mol.

Therefore, a gas with a molar mass of 47.42 g/mol is likely to be [tex]NO_2[/tex]  because the molar mass of [tex]NO_2[/tex]  is 46 g/mol.