1. A child\'s balloon has a diameter of 30 cm and is at room temperature, 25 C.

Question

1. A child's balloon has a diameter of 30 cm and is at room temperature, 25 C. If the pressure in the balloon is 10% higher than atmospheric pressure, find the number of moles of gas in the balloon, assuming it is an ideal gas.

2. At what depth under water will an ideal gas assume one half its volume in atmosphere?

3. A typical oven has dimensions of 80 cm wide, 35 cm high and 40 cm deep. At STP, how many moles of gas fit in the oven? If the temperature is raised to 200 C, and pressure remains unchanged, find the new number of moles of gas in the oven. What percentage of the gas has left? (Assume ideal gas).

Explanation / Answer

1. P = 1.10 Patm = 1.10 (101325 Pa)

P = 111457.5 Pa

V = 4 pi r^3 / 3 = 4 x pi x (0.15)^3 / 3

V = 0.01414 m^3

Applying PV = n RT

(111457.5 )(0.01414) = n (8.314) (273 + 25)

n = 0.636 mol

2. P = 2 Patm

deltaP = Patm = 101325 Pa

deltaP = rho g h

101325 = 1000 x 9.8 x h

h = 10.34 m

3. V = 0.80 x 0.35 x 0.40 =0.112 m^3

P V = n R T

(101325) (0.112) = n (8.34) (273)

n = 5 mol ........Ans

now T = 200 C

(101325) (0.112) = n (8.314) (273 + 200)

n = 2.86 mol .....Ans

% = (5 - 2.86) x 100 / 5

= 42.3 %

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.