Respuesta :

Answer : The pressure of helium gas is, 926.4 mmHg

Explanation :

To calculate the pressure of helium gas we are using ideal gas equation:

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

where,

P = pressure of helium gas = ?

V = volume of helium gas = 645 mL = 0.645 L

T = temperature of helium gas = [tex]31^oC=273+31=304K[/tex]

R = gas constant = 0.0821 L.atm/mole.K

w = mass of helium gas = 0.126 g

M = molar mass of helium gas = 4 g/mole

Now put all the given values in the ideal gas equation, we get:

[tex]P\times 0.645L=\frac{0.126g}{4g/mole}\times (0.0821L.atm/mole.K)\times (304K)[/tex]

[tex]P=1.2189atm=926.4mmHg[/tex]

Conversion used : (1 atm = 760 mmHg)

Therefore, the pressure of helium gas is, 926.4 mmHg

The pressure of helium gas will be "926.4 mmHg".

Given:

  • Volume of helium gas, V = 645 mL or, 0.645 L
  • Temperature, T = 31°C

                                   = 273+31

                                   = 0.645 L

  • Gas constant, G = 0.0821 L.atm/mole.K
  • Mass, w = 0.126 g
  • Molar mass, M = 4 g/mole

By using the Ideal gas equation, we get

→ [tex]PV = nRT[/tex]

or,

→ [tex]PV = \frac{w}{M}RT[/tex]

By substituting the values, we get

→ [tex]P\times 0.645=\frac{0.126}{4 }\times (0.0821)\times (304 )[/tex]

→             [tex]P = 1.2189 \ atm[/tex]

                  [tex]= 926.4 \ mmHg[/tex]

Thus the above response is appropriate.  

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