OnRamps Unit 4 Part 1 Practice Exam

An isolated system allows for the flow of …?

• heat

• kinetic energy

• none of these

• matter

Tags

NGSS.HS-PS3-4

During a thermodynamic process

• all the state functions must increase or stay constant

• all state functions must stay constant

• some state functions may increase, others may decrease and some may stay constant

• all state function must change

Which of the following statements is true?

• Work is the concerted flow of energy and is positive when it is done on the system.

• Heat is the concerted flow of energy and is positive when it is done on the system.

• Work is the concerted flow of energy and is positive when t is done on the surroundings

• Heat is the concerted flow of energy and is positive when it is done on the surroundings.

Tags

NGSS.HS-PS3-4

Consider the following specific heats: copper, 0.384 J/g ∙ ℃; lead, 0.159 J/g ∙ ℃; water 4.18 J/g ∙ ℃; glass 0.502 J/g ∙ ℃. If the same amount of heat is added to identical masses of each f these substances, which substance attains the highest temperature? (Assume that they all have the same initial temperature.)

• Water

• Copper

• Glass

• Lead

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

Which of the following statements is/are true concerning the first law of thermodynamics?

I) The internal energy (U) of the universe is conserved.

II) The internal energy of a system plus that of its surroundings is conserved.

III)The change in internal energy (∆U) of a system and its surroundings can have the same sign.

• I, III

• I only

• I, II, III

• I, II

Which of the following is not a definition of internal energy or change in internal energy

• A measure of the spontaneity of a reaction

• The total energy content of a system

• The sum of heat (q) and work (w)

• A measure of the change in heat of a system at constant volume.

Tags

NGSS.HS-PS3-1

A syringe increases in volume by 3 liters at a constant pressure of 10 atm. Calculate the work in J. (1 l atm = 100 J).

• 3000 J of work on the system

• 3000 J of work on the surroundings.

• 300 J of work on the system

• 300 J of work on the surroundings

Tags

NGSS.HS-PS3-1

A CD player and its battery together do 500 kJ of work, and the battery also releases 250 kJ of energy as heat and the CD player releases 50 kJ at heat due to friction from spinning. What is the change in internal energy of the system, with the system regarded as the battery and CD player together?

• -750 kJ

• +200 kJ

• -800 kJ c

• -200 kJ

Tags

NGSS.HS-PS3-1

A mixture of ice and water is heated to 50℃. What constants are needed to calculate the amount of heat introduced into the system?

• C_ice, ∆H_fus, C_water

• C_water

• C_ice, ∆H_fus, C_water ∆H_vap, C_gas

• ∆H_fus, C_water

Tags

NGSS.HS-PS3-4

Benzene has a melting point of 5.5℃ and a boiling point of 80.1℃. Given the other constants below for benzene (C6H6), which of the following processes would require LEAST amount of energy? Assume in each case the mass of benzene is used.

c_solid = 118.4 J / mol K

c_liquid = 134.8 J / mol K

c_vapor = 82.444 J / mol K

∆H_vap = 30.77 kJ/ mol

∆H_fus = 9.9 kJ/ mol

• Warming benzene from -10℃ to 0℃.

• Melting benzene from 5.5℃

• Warming benzene from 91℃ to 101℃.

• Warming benzene from 65℃ to 75℃

Tags

NGSS.HS-PS3-4