Molecular Physics | Thermodynamics Answers

At 0.0°C and 1.00 atm, 1.00 mol of a gas occupies a volume of 0.0224 m³.

a) What is the number density?

b) Estimate the average distance between the molecules.

c) If the gas is nitrogen (N₂), the principal component of air, what is the total mass? Molar mass of Nitrogen is 14.00674 g/mol.

d) If the gas is nitrogen (N₂), the principal component of air, what is the mass density? Molar mass of Nitrogen is 14.00674 g/mol.

In a certain bimetallic strip, the brass strip is 0.100% longer than the steel strip at a temperature of 287°C. At what temperature do the two strips have the same length? Coefficients of linear expansion for steel α = 12.0 × 10⁻⁶ K⁻¹ and for brass α = 19.0 × 10⁻⁶ K⁻¹

A scuba diver is in fresh water has an air tank with a volume of 0.0100 m³. The air in the tank is initially at a pressure of 1.00 × 10⁷ Pa. Assume that the diver breathes 0.500 L/s of air. Density of fresh water is 1.00 × 10³ kg/m³.

How long will the tank last at depths of 4.10 m?

Incandescent lightbulbs are filled with an inert gas to lengthen the filament life. With the current off (at T = 20.0°C), the gas inside a lightbulb has a pressure of 126 kPa. When the bulb is burning, the temperature rises to 83.7°C. What is the pressure at the higher temperature?

The density of copper at 293 K is 8,940 kg/m³ and its linear expansion coefficient is 17.0 x 10⁻⁶ K⁻¹. Consider a hot cube of copper that is 1.0 cm on a side when its temperature is 1.356 K. What is the cube’s mass? 

A freezer has a coefficient of performance of 2.40. The freezer is to convert 1.80 kg of water at

25.0°C to 1.80 kg of ice at -5.0°C in one hour. (a) What amount of heat must be removed from the

water at 25.0°C to convert it to ice at -5.0°C (b) How much electrical energy is consumed by the

freezer during this hour? (c) How much wasted heat is delivered to the room in which the freezer

sits?

The number density of copper atoms is 8.49×(10^28) atoms (m^-3). If each atoms contributes one free electrons for conduction, examine whether the electron gas is strongly degenerate at room temperature.

1. A sample of an ideal gas is enclosed in a rigid sealed container. At the time of sealing the container contained gas at a temperature of 25.0°C and at a pressure of 101 kPa.
2. The container is cooled down in a refrigerator. What is the pressure inside the container when the temperature has dropped to 5.5 °C? (to 3 s.f and in kPa)

An aluminium baseball has a coefficient of volume expansion of 69×19-⁶°C-¹, the bat has a length of 0.86m at a temperature of 25°C. When the temperature of the bat is increased,the bat expands by 0.00016m. Determine the final temperature of the bat

A spaceship is traveling at half the speed of light (0.5c). Their onboard clock shows that they traveled for a full year. How much time passed on Earth during their “year”? (Give your answer in years)