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 47 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
Great answer, keep it coming :)

Liamb2179

  • Member
  • Posts: 365
Reply 3 on: Yesterday
Excellent

« previous next »
 

Did you know?

The modern decimal position system was the invention of the Hindus (around 800 AD), involving the placing of numerals to indicate their value (units, tens, hundreds, and so on).

Did you know?

Many supplement containers do not even contain what their labels say. There are many documented reports of products containing much less, or more, that what is listed on their labels. They may also contain undisclosed prescription drugs and even contaminants.

Did you know?

Malaria was not eliminated in the United States until 1951. The term eliminated means that no new cases arise in a country for 3 years.

Did you know?

Cytomegalovirus affects nearly the same amount of newborns every year as Down syndrome.

Did you know?

Symptoms of kidney problems include a loss of appetite, back pain (which may be sudden and intense), chills, abdominal pain, fluid retention, nausea, the urge to urinate, vomiting, and fever.

Furchgott's discovery that endothelial cells produce a vasodilating substance. Furchgott's discovery that endothelial cells produce a vasodilating substance.
Concentric double-pipe heat exchanger for counter-current flow Concentric double-pipe heat exchanger for counter-current flow
Excess heat capacity chart Excess heat capacity chart
A boiling-liquid, expanding-vapor explosion (BLEVE). The burning propane cylinder on the left is not ... A boiling-liquid, expanding-vapor explosion (BLEVE). The burning propane cylinder on the left is not ...
Find an equation of the tangent line to the graph of f(x) = sqrt(x) / (x+1) at the point x=1 Find an equation of the tangent line to the graph of f(x) = sqrt(x) / (x+1) at the point x=1
A melting profile shows the increase in UV absorption versus temperature A melting profile shows the increase in UV absorption versus temperature
Video: Muscular Dystrophy

For a complete list of videos, visit our video library