This topic contains a solution. Click here to go to the answer
« previous next »

Author Question: A substance has a melting point of 20C and a heat of fusion of 3.5 104 J/kg. The boiling point is ... (Read 122 times)

clmills979

  • Hero Member
  • *****
  • Posts: 551
on: Jul 29, 2018
A substance has a melting point of 20C and a heat of fusion of 3.5  104 J/kg. The boiling point is 150C and the heat of vaporization is 7.0  104 J/kg at a pressure of 1.0 atm.
 
  The specific heats for the solid, liquid, and gaseous phases are 600 J/(kgK), 1000 J/(kgK), and 400 J/(kgK), respectively. The quantity of heat given up by 0.50 kg of the substance when it is cooled from 170C to 88C, at a pressure of 1.0 atmosphere, is closest to
  A) 30 kJ. B) 70 kJ. C) 44 kJ. D) 21 kJ. E) 14 kJ.

Question 2

A metal having a work function of 2.8 eV is illuminated with monochromatic light whose photon energy is 3.9 eV.
 
  What is the threshold frequency for photoelectron production? (h = 6.626  10-34 J  s, 1 eV = 1.60  10-19 J)
  A) 6.8  1014 Hz
  B) 2.7  1014 Hz
  C) 7.6  1014 Hz
  D) 8.5  1014 Hz
  E) 9.4  1014 Hz


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

mariahkathleeen

  • Sr. Member
  • ****
  • Posts: 337
Reply #1 on: Jul 29, 2018
Answer to Question 1

B

Answer to Question 2

A


clmills979

  • Member
  • Posts: 551
Reply 2 on: Jul 29, 2018
Wow, this really help

brbarasa

  • Member
  • Posts: 308
Reply 3 on: Yesterday
Gracias!

« previous next »
 

Did you know?

There used to be a metric calendar, as well as metric clocks. The metric calendar, or "French Republican Calendar" divided the year into 12 months, but each month was divided into three 10-day weeks. Each day had 10 decimal hours. Each hour had 100 decimal minutes. Due to lack of popularity, the metric clocks and calendars were ended in 1795, three years after they had been first marketed.

Did you know?

This year, an estimated 1.4 million Americans will have a new or recurrent heart attack.

Did you know?

Looking at the sun may not only cause headache and distort your vision temporarily, but it can also cause permanent eye damage. Any exposure to sunlight adds to the cumulative effects of ultraviolet (UV) radiation on your eyes. UV exposure has been linked to eye disorders such as macular degeneration, solar retinitis, and corneal dystrophies.

Did you know?

If you use artificial sweeteners, such as cyclamates, your eyes may be more sensitive to light. Other factors that will make your eyes more sensitive to light include use of antibiotics, oral contraceptives, hypertension medications, diuretics, and antidiabetic medications.

Did you know?

GI conditions that will keep you out of the U.S. armed services include ulcers, varices, fistulas, esophagitis, gastritis, congenital abnormalities, inflammatory bowel disease, enteritis, colitis, proctitis, duodenal diverticula, malabsorption syndromes, hepatitis, cirrhosis, cysts, abscesses, pancreatitis, polyps, certain hemorrhoids, splenomegaly, hernias, recent abdominal surgery, GI bypass or stomach stapling, and artificial GI openings.

Nancy Rubins, Pleasure Point. Nancy Rubins, Pleasure Point.
Co-current flow in a concentric tube heat exchanger Co-current flow in a concentric tube heat exchanger
Distillation column with heat pump Distillation column with heat pump
Instruct recipient on giving you feedback immediately if heat becomes too intense. Remind the person ... Instruct recipient on giving you feedback immediately if heat becomes too intense. Remind the person ...
Apply the substance to the arm with long, smooth strokes, then cover the arm and abdomen with the ... Apply the substance to the arm with long, smooth strokes, then cover the arm and abdomen with the ...
Heat and Cold Stress Compared Heat and Cold Stress Compared
Video: Component of feedback systems & Communication and regulation of body systems

For a complete list of videos, visit our video library