Thermodynamics Questions and Answers

a A tank contains one mole of nitrogen gas at a pressure of 6 75 atm and a temperature of 26 0 C The tank which has a fixed volume is heated until the pressure inside triples What is the final temperature of the gas C b A cylinder with a moveable piston contains one mole of nitrogen again at a pressure of 6 75 atm and a temperature of 26 0 C Now the cylinder is heated so that both the pressure inside and the volume of the cylinder double What is the final temperature of the gas C

Click to see additional instructions Questions 1 10 Convert the following temperatures into the units specified 10 Core center of the Sun 1 5 107 C x 107 K Calculate and enter your final answer to at least 2 significant figures There is no penalty for including too many significant figures but rounding to too few sig figs may cause Laulima to judge your answer to be wrong Do NOT enter units with your answer enter only a numerical response Laulima will count non numerical answers as incorrect Partial credit is NOT possible

1 A steam engine takes in 90 000 J of heat each cycle from a reservoir at a temperature of 500K The engine does 27 000 J of work each cycle What is the actual efficiency of this engine If the exhausted heat is applied to 10 kg of water at 0 C what is the Carnot efficiency The heat of fusion of water is 3 33 x 105 J kg and the specific heat of water is 4186 J kg C

16 A 200 gram liquid sample of Alcohol Y is prepared at 6 C The sample is then added to 400 g of water at 20 C in a sealed styrofoam container When thermal equilibrium is reached the temperature of th alcohol water solution is 12 C What is the specific heat capacity of the alcohol Assume the sealed container is an isolated system The specific heat capacity of water is 4 19 kJ kg C 4 88 kJ kg xe2 x88 x99 C 3 72 kJ kg xe2 x88 x99 C 3 14 kJ kg xe2 x88 x99 C 4 14 kJ kg xe2 x88 x99 C

0 40 m3 9 A 700 g quantity of an ideal gas undergoes a reversible isothermal compression at a temperature of 330 K The compression reduces the volume of the gas f from molecular mass of the gas is 38 0 g mol What is the entropy change for the gas in SI units O 150 00 150 57 57 initially to 0 15 m3 All changes s finally The

When 200 0 mL of water is heated from 15 0 C to 40 0 C how much thermal energy is absorbed by the water Since the quantity of heat equation is based on the mass of an object we must first determine the mass in kilograms of 200 0 mL of water To do this we use the density of water which is 1 0 g mL We then calculate the change in the temperature of the water using the equation AT T T Finally we use the quantity of heat equation Q mcAT along with the mass of the water m the specific heat capacity of water C and the change in temperature of the water AT to determine how much thermal energy is absorbed by the water Given V 200 0 mL T 15 0 C T 40 0 C C 4 18 x 10 J kg C Required Q Analysis AT T T Q mcAT 1g 1 mt Solution m 200 0 mt x m 0 2000 kg AT 1 2 T X 40 0 C 15 0 C 0 2000 kg 4 18 x 10 Q 2 09 x 10 J 1 kg 1000 g AT 25 0 C Now that we have calculated the mass of the water in kilograms and the change in temperature we may use these values to calculate the quantity of heat Q mcAT J kg 25 0 orbe 209 x 101 of thermal energy

2Po Po V 2V An ideal gas is carried around the cyclic process described by the diagram Let Po 4 00 atm and 485 J 1220 J 2420 J 2280 J V 4850 J Vo 3 00 liters How much work does the gas do in one cycle

10 A compression at a constant pressure of 40 kPa is performed on 6 0 moles of an ideal monatomic gas work done by the gas zero 12 kJ 12 kJ 4 8 kJ 4 8 kJ Cy 1 5R The compression reduces the volume of the gas from 0 24 m to 0 12 m What is the

An ideal gas is held in a non rigid container that is kept at a constant temperature 295 K The pressure on the container is reduced from 50 Pa to 30 Pa If the initial volume of the gas was 0 75 m what is the final volume C1 25 m 0 45 m 0 8 m 2 25 m

A cylinder with a moveable piston inside it holds a volme of air V 0 129 m at an initial pressure P 25 5 kPa The piston moves so that the final volume Vy is 0 904 m the temperature of the gas does not change during this process See the diagram shown Answer the three parts below using three sig figs Part A This gas process would be classified as what Part B Consider any work or heat flow occuring with this process Pick all the statements that are correct There mus be heat entering the gas somehow There must be heat leaving the gas somehow There is no heat entering or leaving the gas The environment is performing work on the gas Gas is performing work on the environment There is no work involved in this process P kPa 8 10 0 5 V m 1 0

A 88 kg sample of liquid water is cooled from 0 C to 43 C It freezes in the process How much heat is liberated For water O O 37 100 kJ 21 600 kJ 1470 kJ 45 200 kJ L 334 kJ kg and All chane v 2257 kJ kg The specific heat capacity of ice is 2 05 kJ kg C

What are the three parts of the 2nd law of thermodynamics Heat will not flow spontaneously from a cold to a hot body You cannot construct an engine that does nothing but convert heat to useful work Every isolated system becomes more disordered with time Energy and mass are interchangeable The acceleration produced on a body by a force is proportional to the magnitude of the force Objects in motion stay in motion unless acted upon by an external force For every action there is an equal and opposite reaction

A temperature difference of 50 C is the same as a difference of 50 K 323 K 223 K O 223 K 323 K

An ideal gas is at a pressure 1 00 x 105 N m and a volume 2 00 m If the gas is compressed to a volume 1 00 m while the temperature remains constant what will be the new pressure in the gas 2 00 x 105 N m O0 500 x 105 N m 1 00 x 105 N m The answer depends on the mass of the gas particles 4 00 x 105 N m

1500 J of work is equivalent to how much heat A 6 279 kcal OB 6 279 000 cal C 358 cal OD 358 kcal

If it is known that two bodies are in thermal equilibrium one can conclude that they must be in thermal equilibrium with a third body there must be a net heat flow between them the bodies must be at different temperatures some shared physical property must be changing they must be at the same temperature

5 The Electric Field Lines are a Symmetric b Not symmetric c Linear d No linear 6 Electric Potential due to a point charge is a Inversely proportional to the charge q b Directly proportional to the point charge c Absolutely not related d None of the above 7 The capacitance of a parallel plates capacitor is a Directly proportional to the surface area of the Plate b Inversely proportional to the surface area of the Plate c Equal to the total energy of the capacitor d All the above 8 Thermodynamics is a A part of physics that force the air to move around the planet b A part of physics that studies the heat flow between systems al 4 gravitational ferss d They 12 A 13 A 14 15

Explain how the procedure described in each case will affect the pressure in a closed cylinder of gas a The volume is decreased at constant temperature b The volume is increased at constant temperature c volume The temperature is increased at constant d The cylinder is opened and half of the gas particles are allowed to escape but the volume remains constant e For each of the above scenarios is AW and AQ positive negative or zero a b c AW AQ

A sample of solid 37 1 C what is the Answer

An example of a thermometric property is the volume of a gas the pressure of a confined gas the electrical resistance of an electrical conductor the length of a column of mercury All of these are correct

theexpertta com tracking id IF76 E7 EE 40 A291 31085 In accordance with Expert TA s Terms of Service copying this information to any solutions sharing web strictly forbidden Doing so may result in termination of your Expert TA Account 25 Part a Calculate the number of moles n contained in this ideal gas n 21 204 n 21 2 Correct 25 Part b Calculate the temperature of the gas in kelvins after it undergoes the isobaric expancion Ta 1008 Comment

In conduction, what happens to the heat transfer per unit time when the thermal conductivity decreases? (A) The heat flow will increase. (B) The heat flow will remain constant. (C)The heat flow will partially increase and then will decrease. (D) The heat flow will partially increase.

A mixture of hydrogen and oxygen is enclosed in a rigid insulting cylinder. It is ignited by a spark. The temperature and the pressure both increase considerably. Assume that the energy supplied by the spark is negligible, what conclusions may be drawn by application of the first law of thermodynamics?

A gas with initial state variables pi. V₁, and Ti is cooled in an isochoric process until p₂ =1/3 P₁. By what factor does the volume change? By what factor does the temperature change?

One mole of neon gas is heated from 316 K to 410 K at constant pressure. Note that neon has a molar specific heat of c = 20.79 J/mol K for a constant-pressure process. (a) Calculate the energy Q transferred to the gas. (b) Calculate the change in the internal energy of the gas. (c) Calculate the work done on the gas.

An ideal gas is enclosed in a cylinder with a movable piston on top of it. The piston has a mass of 8,000 g and an area of 5.00 cm² and is free to slide up and down, keeping the pressure of the gas constant. (a) How much work is done on the gas as the temperature of 0.255 mol of the gas is raised from 30.0°C to 325°C? _____J (b) What does the sign of your answer to part (a) indicate? The gas does positive work on its surroundings. There is no work done, by the gas or the surroundings. The surroundings do positive work on the gas.

Gas in a container is at a pressure of 1.8 atm and a volume of 9.0 m³. (a) What is the work done on the gas if it expands at constant pressure to twice its initial volume? (b) What is the work done on the gas if it is compressed at constant pressure to one quarter of its initial volume?

Consider a vertical tube open at both ends. The tube consists of two parts, each of different cross sections and each part having a piston which can move smoothly in respective tubes. The two pistons are joined together by an inextensible wire. The combined mass of the two pistons is 5kg and area of cross section of the upper piston is 10cm² greater than that of the lower piston. Amount of gas enclosed by the pistons is 1 mol. When the gas is heated slowly, pistons move by 50cm. Find the rise in the temperature of the gas in the form X/RK, where R is universal gas constant. Use g = 10m/s² and outside pressure = 105 N/m²

A thin uniform bar lies on a frictionless horizontal surface and is free to move in any way on the surface. Its mass is 0.16 kg and length is 1.7 m .Two particles each of mass 0.08 kg are moving on the surface and towards the bar in the direction perpendicular to the bar, one with a velocity of 10 m/s and other with velocity 6 m/s. If collision between particles and bar is completely inelastic, both particle strike with the bar simultaneously. The velocity of centre of mass after collision is:

The rate constant of a reaction at 300 K is 5.0 × 10-minute-¹ . The temperature was increased by 20 K and the value of rate constant'K' increased three times. Calculate the energy of activation of the reaction? What will be the value of rate constant at 37°C ?

One spring day, Aisha noted the time of day and the temperature, in degrees Fahrenheit. Her findings are as follows: At 6 a.m., the temperature was 52° F. For the next 6 hours, the temperature rose 1° per hour. For the next 5 hours, it rose 3° per hour. The temperature then stayed steady until 6 p.m. For the next 2 hours, the temperature dropped 3° per hour. The temperature then dropped steadily until the temperature was 66° at midnight. On the set of axes below, graph Aisha's data.

With temperature held constant, the pressure of a gas in a cylinder with a movable piston is increased from 14 kPa to 53 kPa. The initial volume of the gas in the cylinder is 0.42 m³. (a) What is the final volume of the gas after the pressure is increased?

. A fixed quantity of an ideal gas has an initial pressure, volume, and temperature of P₁, V₁, and T₁, respectively. The temperature of the gas is doubled. Which of the following sets of values for the final pressure and volume is possible? (a) P₁ and V₁ (b) P, and 3 (c) 2P, and 2V; (d) 2P, and V₁

The specific heat of zinc is 386 joules per kilogram per Celsius degree. The amount of heat energy required to raise the temperature of 0.25 kilogram of zinc from 0°C to 28°C is most nearly (a) 1500 J (b) 2700 J (c) 3500 J (d) 4300 J

According to Newton's Law of Cooling, if a body with temperature T₁ is placed in surroundings with temperature To. different from that of T₁, the body will either cool or warm to temperature T(t) after t minutes, where T(t)= To +(T₁-To)ekt. A metal pan with temperature 125°F is placed in a freezer with temperature 0°F. After 5 minutes, the temperature of the pan is 83°F. Use Newton's Law of Cooling to find the pan's temperature after 15 minutes. After 15 minutes the pan will have a temperature of (Round to the nearest integer.) F.

Air with a temperature of 27 °C receives heat at constant volume until the temperature reaches 927°C. The specific heat of air varies with temperature as Cp = 0.9167 + (2.577 x 10^-4) (3.974 x 10^-8) T² in kJ/kg-k a. Find the change of internal energy in kJ/kg. b. Find the change of enthalpy in kJ/kg.

The coefficient of performance of a refrigerator is 3.00. The compressor uses 30.0 J of energy per cycle. Part A How much heat energy is exhausted per cycle? Express your answer with the appropriate units. If the hot-reservoir temperature is 25 °C, what is the lowest possible temperature in °C of the cold reservoir? Express your answer in degrees Celsius.

An ideal gas expands isothermally, performing 3.00x10^3 J of work in the process. Calculate the change in internal energy of the gas.

8.4 moles of an ideal monatomic gas expand adiabatically, performing 8800 J of work in the process. What is the change in temperature of the gas during this expansion?

0.191 moles of an ideal gas are confined to a rigid container (V = 1.18 L). The pressure of gas at T = 353 K was 8.25 atm. What is the pressure (in atm) at T = 1,049?

Gas in a container is at a pressure of 2.0 atm and a volume of 5.0 m³. (a) What is the work done on the gas if it expands at constant pressure to twice its initial volume? (b) What is the work done on the gas if it is compressed at constant pressure to one-quarter of its initial volume?

In each cycle of its operation, a heat engine expels 3,000 J of energy and performs 2,000 J of mechanical work. (a) How much thermal energy must be added to the engine in each cycle? (b) Find the thermal efficiency of the engine.

You would like to raise the temperature of an ideal gas from 295 K to 950 K in an adiabatic process.

What type of change can be reversed? Physical change Chemical change Both physical and chemical changes Neither a physical nor a chemical change

Air at 20°C in the cylinder of a diesel engine is compressed from an initial pressure of 1.3 atm and volume of 864 cm³ to a volume of 163 cm³. Assume air behaves as an ideal gas with gamma (y=1.4) and the compression is adiabatic with changing in temperatutre. Find the final pressure of the air. Hint: for adiabatic process of an ideal gas, we can use: P₁ V = P₁ V Note: 1atm = 1.01 x 10^5 Pa

An ideal gas undergoes an isovolumetric process from initial pressure of 8 kPa to the final pressure of 90 kPa. If the final temperature of the gas was 807 K then what is its initial temperature (in Kelvins)?

The specific heat capacity of a pure substance can be found by dividing the heat needed to change the temperature of a sample of the substance by the mass of the sample and by the change in temperature. The heat capacity of a certain substance has been measured to be 2.90 J/g °C .Suppose 283. g of the substance are heated until the temperature of the sample has changed by 13.6 °C. Write an equation that will let you calculate the heat Q that was needed for this temperature change. Your equation should contain only symbols. Be sure you define each symbol.

A 10 cm thick piston sits inside a cylinder containing 0.1 kg of water. An internal flange is built into the cylinder and serves to stop the control volume from expanding. The mixture is expanded from an initial value of Vi = 0.82 m³ and Ti = 20 °C. The cross-sectional area of the piston is 1.43 m². a) Enough heat is added so that the piston just barely comes in contact with the flange. Determine the work done W₁₂ and heat added Q₁₂.

Air enters an adiabatic nozzle steadily at 300 kPa, 200°C, and 45 m/s and leaves at 100 kPa and 180 m/s. The inlet area of the nozzle is 110 cm². The gas constant of air is 0.287 kPa.m³/kg.K. The specific heat of air at the anticipated average temperature of 450 K is Cp=102 kJ/kg.°C. Determine the exit temperature of the air.

4. Hydrogen gas occupies a volume of 2.1 cm³ at 30°C and normal atmospheric pressure. A)Determine the number of molecules of gas in the container b. Find the mass of the gas in the container. c. If mass of the gas is reduced in two times keeping the same volume and temperature, what is the pressure of the gas now.