Question

1. A balloon is floating around outside your window. The temperature outside is -15 ∘C , and the air pressure is 0.800 atm . Your neighbor, who released the balloon, tells you that he filled it with 4.00 moles of gas. What is the volume of gas inside this balloon? Express your answer to three significant figures and include the appropriate units. Vballoon =

2. A 18.0 L gas cylinder is filled with 9.80 moles of gas. The tank is stored at 25 ∘C . What is the pressure in the tank?

Express your answer to three significant figures and include the appropriate units. Ptank =

3. A 180. L kiln is used for vitrifying ceramics. It is currently operating at 1125 ∘C , and the pressure is 1.050 atm . How many moles of air molecules are within the confines of the kiln?

Express your answer to three significant figures and include the appropriate units. nair =

4. A 20.0 L gas cylinder has been filled with 4.40 moles of gas. You measure the pressure to be 4.90 atm . What is the temperature inside the tank?

Express your answer to three significant figures and include the appropriate units. Ttank =

5. How many moles of gas must be forced into a 4.8 L tire to give it a gauge pressure of 32.4 psi at 30 ∘C? The gauge pressure is relative to atmospheric pressure. Assume that atmospheric pressure is 14.5 psiso that the total pressure in the tire is 46.9 psi. n = ____ mol

Answer 1

Part 1)

Here,

Temperature in Kelvin=-15 ^OC = -15 + 273 = 258 K

Air pressure = 0.800 atm

Moles of the gas inside the balloon = 4.00

Using ideal gas equation, PV = nRT

Where, P is the pressure, V is the volume, n is the number of moles, R is the gas constant and T is the temperature.

On rearranging the ideal gas equation,

V= nRT/P = (4 moles x 258 K x 0.0821 L atm K^-1 mol^-1)/ 0.8 atm = 105.9 L

Volume of gas inside the balloon = 105.9 L

Part 2)

Using ideal gas equation, PV = nRT

Here,

Temperature in Kelvin= 25 ^OC = 25 + 273 = 298 K

Volume of the cylinder = 18.0 L

Moles of the gas inside the cylinder = 9.80 moles

On rearranging the ideal gas equation,

P = nRT/V = (9.8 moles x 298 K x 0.0821 L atm K^-1 mol^-1)/ 18 L = 13.32 atm

Pressure inside the tank = 13.3 atm

Part 3)

Using ideal gas equation, PV = nRT

Here,

Temperature in Kelvin= 1125 ^OC = 1125 + 273 = 1398 K

Volume of the kiln = 180 L

Pressure inside the Kiln = 1.05 atm

Moles of the gas inside kiln =?

On rearranging the ideal gas equation,

n = PV/RT = (1.05 atm x 180 L)/(1398 K x 0.0821 L atm K^-1 mol^-1) = 1.646 moles

Moles of air molecules within the kiln = 1.64 moles

Part 4)

Using ideal gas equation, PV = nRT

Here,

Temperature in Kelvin =?

Volume of the cylinder = 20 L

Pressure inside the cylinder = 4.90 atm

Moles of the gas inside cylinder = 4.40 moles

On rearranging the ideal gas equation,

T = PV/Rn = (4.90 atm x 20 L)/(4.40 moles x 0.0821 L atm K^-1 mol^-1) = 271 K = -1.71 ^OC

Temperature inside the tank = 271 K = -1.71 ^OC