Water is heated to boiling under a pressure of 1.0 atm. When an electric current of 0.50 A from a 12V supply is passed for 300 s through a resistance in thermal contact with it, it is found that 0.798 g of water is vaporized. Calculate the molar internal energy and enthalpy changes at the boiling point (373.15 K).

Water is heated to boiling under a pressure of 1.0 atm. When an electric current of 0.50 A from a 12V supply is passed for 300 s through a resistance in thermal contact with it, it is found that 0.798 g of water is vaporized. Calculate the molar internal energy and enthalpy changes at the boiling point (373.15 K).

Principles of Physics: A Calculus-Based Text

5th Edition

ISBN:9781133104261

Author:Raymond A. Serway, John W. Jewett

Publisher:Raymond A. Serway, John W. Jewett

Chapter16: Temperature And The Kinetic Theory Of Gases

Section: Chapter Questions

Problem 4P

See similar textbooks

Similar questions

A 1.00 mol sample of water vapour is enclosed in a rigid container equipped with a 9.97 Q electric resistance heater. When a current of 0.200 A is passed through the resistor for 100.0 s, the temperature of the apparatus was observed to increase by 0.465 K. Separate measurements on the evacuated container show that the heat capacity of the container and resistance heater is 60.50 J. K-1 Calculate the value of Cy for the gaseous water (water vapour).
A plate (74 + 0.3) m long and (74 + 0.1) m wide, with a thickness of (74 + 12) mm is made from stainless steel ( k= 16 W/mK). The temperature at the bottom surface of the plate is 100 °? maintained by an electrical heater supplied by 200 V and 0.25 A. In a steady-state condition, assuming that the plate is perfectly insulated on all sides except top surface, find temperature at the top surface of the plate.
In an experiment, the temperature of a hot gas stream is to be measured by a thermocouple with a spherical junction. Due to the nature of this experiment, the response time of the thermocouple to register 99 percent of the initial temperature difference must be within 5 s. The properties of the thermocouple junction are k = 35 W/m·K, r = 8500 kg/m3, and cp = 320 J/kg·K. If the heat transfer coefficient between the thermocouple junction and the gas is 250 W/m2·K, determine the diameter of the junction.
Suppose a tank contains 714 m3 of neon (Ne) at an absolute pressure of 1.01x105 Pa. The temperature is changed from 293.2 to 294.7 K. What is the increase in the internal energy of the neon?
A computer in a well-sealed and well-insulated (thermally) room, dissipates energy at a rate of 500W. The room has 10 mw kg of drinking water, and 50 ma kg of air, with all material at 300K and 100kPa initially. Assuming all the mass (water and air) heats up uniformly, how long will it take to increase the temperature 5 dT °C?.
A power plant burns coal to produce pressurized steam at 554 K. The steam then condenses back into water at a temperature of 334 K If the plant operates at 50.0% of its maximum efficiency and its power output is 1.23 * 10 ^ 8 * v means of a cooling tower ? at what rate must heat be removed by means of cooling tower?
In a certain experiment, cylindrical samples of diameter 4 cm and length 7 cm. The two thermocouples in each sample are placed 3 cm apart. After initial transients, the electric heater is observed to draw 0.6 A at 110 V, and both differential thermometers read a temperature difference of 8°C. Determine the thermal conductivity of the sample
A thermocouple, with a spherical junction diameter of 0.5 mm, is used for measuring the temperature of hot air flow in a circular duct. The convection heat transfer coefficient of the air flow can be related with the diameter (D) of the spherical junction and the average air flow velocity (V) as h = 2.2(V/D)0.5, where D, h, and V are in m, W/m2?K and m/s, respectively. The properties of the thermocouple junction are k = 35 W/m?K, r = 8500 kg/m3, and cp = 320 J/kg?K. Determine the minimum air flow velocity that the thermocouple can be used, if the maximum response time of the thermocouple to register 99 percent of the initial temperature difference is 5 s.
The thermal contact conductance at the interface of two 1-cm-thick copper plates is measured to be 18,000 W/m2·K. Determine the thickness of the copper plate whose thermal resistance is equal to the thermal resistance of the interface between the plates.
In a certain particle accelerator, protons travel around a circular path of diameter 23.0 m in an evacuated chamber, whose residual gas is at 295 K and 1.00 * 10-6 torr pressure. (a) Calculate the number of gas molecules per cubic centimeter at this pressure. (b) What is the mean free path of the gas molecules if the molecular diameter is 2.00 * 10-8 cm?
Nitrogen is released at one end of a pressure chamber of length 30 meters and takes 7 hours and 44 minutes to diffuse from one end of the chamber to the other. Given that the mean radius of a nitrogen molecule is 0.15 nm, and the chamber is at room temperature (∼300 K), determine the pressure to which the chamber was set (in atm).
if some of your hot metal remained in the test tube when it was transfered to the calorimeter would its calculated molar mass be greater than, less than, or unchanged from the actual value?