Test Unit 9 Thermochemistry

An equal mass sample of each substance absorbs 50 J of heat. Identify the substance that undergoes the largest temperature change.

• lead

  C = 0.13 J/g^oC

• granite

  C = 0.79 J/g^oC

• dry air

  C = 1.01 J/g^oC

• ice

  C = 2.11 J/g^oC

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

As kinetic energy of molecules increases, ______

• Temperature increases.

• Temperature decreases.

• Temperature is not affected by kinetic energy.

Tags

NGSS.MS-PS1-4

• -3.48 J

• 3.48 J

• 1704 J

• -1704 J

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

NGSS.MS-PS3-5

Identify the following as examples of Kinetic Energy or Potential Energy.

Groups:

(a) Kinetic Energy

,

(b) Potential Energy

• A moving vehicle

• Ice melting

• A cell phone with no battery power

• Food sitting on a table

• Gas molecules at 10⁰C

• A battery

Tags

NGSS.MS-PS3-5

Identify the following as examples of Endothermic or Exothermic processes.

Groups:

(a) Endothermic

,

(b) Exothermic

• Freezing

• Reaction container is cold to the touch

• Evaporation

• Combustion reaction

• Condensation

• Melting

• Reaction container is hot to the touch

• Sublimation

Tags

NGSS.MS-PS1-4

Identify the following reactions as Endothermic or Exothermic reactions.

 

Groups:

(a) Endothermic

,

(b) Exothermic

• Energy Reactants > Energy Products

• CaCO₃ --> CaO + CO₂     ΔH = +178 kJ

• Q = - 45,000 J

• CH₄ + 2O₂ --> CO₂ + 2H₂O + Energy

• 2H₂ + O₂ --> 2H₂O ΔH = -75 kJ

• Energy Products > Energy Reactants

• 3CO + 2Fe + Energy --> 3C + Fe₂O₃

• Q = +5,000 J

Tags

NGSS.MS-PS3-4

NGSS.MS-PS3-5

Define Temperature

• Measure of the average kinetic energy of molecules.

• Measure of the heat energy of molecules.

• Measure of heat flow of molecules.

• Measure of the amount of energy absorbed by molecules when heated.

Thermal energy ALWAYS moves from _____ to _____.

• solid to liquid
• ice to water
• hot to cold
• solid to gas

Tags

NGSS.MS-PS1-4

The flow of thermal energy from warm objects to cool objects is called ______.

• heat flow

• air movement

• friction
• energy

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NGSS.MS-PS3-3

What would be the effect on the particles if more heat is supplied to the system?

• Particles would slow down

• Particles would stop moving

• Particles would speed up

• Particles would not be effected

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-5