contestada

5.137 A person inhales air richer in O2 and exhales air richer in CO2 and water vapor. During each hour of sleep, a person exhales a total of about 300 L of this CO2-enriched and H2O-enriched air. (a) If the partial pressures of CO2 and H2O in exhaled air are each 30.0 torr at 37.0ðC, calculate the mass (g) of CO2 and of H2O exhaled in 1 h of sleep. (b) How many grams of body mass does the person lose in 8 h of sleep if all the CO2 and H2O exhaled come from the metabolism of glucose?

Respuesta :

znk

Answer:  

(a) 20.5 g O₂, 8.38 g H₂O; (b) 230 g  

Step-by-step explanation:  

(a) Masses of CO₂ and H₂O  

pV = nRT            Divide each side by RT  

n = (pV)/(RT)  

p = 30.0 torr      Convert to atmospheres  

p = 30.0 × 1/760 = 0.039 47 atm  

V = 300 L  

R = 0.082 06 L·atm·K⁻¹mol⁻¹  

T = (37.0 + 273.15) K = 310.15 K  

n = (0.039 47 × 300)/(0.082 06 × 310.15)  

n = 0.465 mol  

Mass of CO₂ = 0.465 × 44.01 = 20.5 g  

Mass of H₂O = 0.465 × 18.02 = 8.38 g

===============  

(b) Mass lost during sleep  

Mass lost in 1 h = 20.5 + 8.38 = 28.9 g  

Mass lost in 8 h = 8 × 28.9     = 230 g

pstnonsonjoku

228.16 g of body mass is lost in 8 hours of sleep.

From the question, we can obtain the number of moles of each gas as follows;

Partial pressure of each gas= 30 torr or 0.039 atm

Volume of the gases =  300 L

Temperature of the gases = 37.0°C + 273 = 310 K

R = 0.082 atmLmol-1K-1

From PV =nRT

n = PV/RT =  0.039 atm × 300 L/0.082 atmLmol-1K-1  × 310 K

n = 0.46 moles of each gas

Hence;

Mass of CO2 lost in 1 hour =  0.46 moles × 44 g/mol = 20.24 g

Mass of water vapor lost in 1 hour = 0.46 moles × 18 g/mol = 8.28 g

If 20.24 g of CO2 is lost in 1 hour of sleep, in 8 hours of sleep;

8 × 20.24 g = 161.92 g of CO2 is lost.

Similarly, if 8.28 g of water vapor is lost in 1 hour of sleep, in 8 hours of sleep; 8 × 8.28 g = 66.24 g of water vapor is lost

Since both the CO2 and water vapor come from metabolism, total body mass lost in 8 hours of sleep = 161.92 g + 66.24 g  = 228.16 g

Learn more: https://brainly.com/question/9743981

Otras preguntas