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(a) Calculate the temperature of the gas in Kelvin. K (b) Use the ideal gas law

ID: 1485155 • Letter: #

Question

(a) Calculate the temperature of the gas in Kelvin.
K

(b) Use the ideal gas law to calculate the number of moles of gas in the tank.
mol

(c) Use the periodic table to compute the molecular weight of carbon dioxide, expressing it in grams per mole.
g/mol

(d) Obtain the number of grams of carbon dioxide in the tank.
g

(e) A fire breaks out, raising the ambient temperature by 224.0 K while 82.0 g of gas leak out of the tank. Calculate the new temperature and the number of moles of gas remaining in the tank.


(f) Using the ideal gas law, find a symbolic expression for the final pressure, neglecting the change in volume of the tank. (Use the following as necessary: ni, the initial number of moles; nf, the final number of moles; Ti, the initial temperature; Tf, the final temperature; and Pi, the initial pressure.)


(g) Calculate the final pressure in the tank as a result of the fire and leakage.
Pa

temperature     K number of moles     mol

Explanation / Answer

A 23.0-L tank of carbon dioxide gas (CO2) is at a pressure of 9.90 105 Pa and temperature of 21.0°C.

23 L = 0.023 m3

(a) Calculate the temperature of the gas in Kelvin.
21 + 273 = 294 K


(b) Use the ideal gas law to calculate the number of moles of gas in the tank.
mol

PV = nRT

n = PV/ RT

= 9.90 x 105 x 0.023 / 8.31 x 294

= 9.32 moles

(c) Use the periodic table to compute the molecular weight of carbon dioxide, expressing it in grams per mole.
g/mol

Wc + 2Wo = 12 + (16 x2) = 44 g/mole

(d) Obtain the number of grams of carbon dioxide in the tank.
9.32 x 44 = 410.08 g

(e) A fire breaks out, raising the ambient temperature by 224.0 K while 82.0 g of gas leak out of the tank. Calculate the new temperature and the number of moles of gas remaining in the tank.

temperature    

294 + 224 = 518 K

number of moles    

(410.08 – 82) / 44 = 7.46 mol


(f) Using the ideal gas law, find a symbolic expression for the final pressure, neglecting the change in volume of the tank. (Use the following as necessary: ni, the initial number of moles; nf, the final number of moles; Ti, the initial temperature; Tf, the final temperature; and Pi, the initial pressure.)

Pf = nf RTf/V
(g) Calculate the final pressure in the tank as a result of the fire and leakage.
Pf = 7.46 x 8.31 x 518 / 0.023 = 1396181.16 = 1.4 x 106 Pa

temperature    

294 + 224 = 518 K

number of moles    

(410.08 – 82) / 44 = 7.46 mol