Thermodynamics Chemistry

Heat is defined as

• the transfer of thermal energy from one object to another due to temperature difference

• the temperature of a solid, liquid, or gas

• The kinetic energy of a solid, liquid, or gas.

Tags

NGSS.HS-PS3-4

Which direction will the heat flow while this person holds a hot cup of tea?

• from the cup to her hand

• from her hand to the cup

• no heat is transferred

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-5

If I am eating 3000 calories a day, how many Joules of energy is that?

• 12 035 J

• 716 J

• 12, 570 J

If I lost 850 J of energy as heat, how many calories did I burn?

• 850 calories

• 3,561 calories

• 203 calories

What is true about thermodynamically favorable reactions?

• They need outside energy to be put in

• They always increase entropy

• They always have a negative ΔH

• ΔG is positive

The units for specific heat are Joules/gxC. Specific heat is a measure of how many Joules of energy it takes to raise the temperature of a substance. Which substance takes the most amount of energy to raise the temperature?

• Water

• Basalt

• Iron

• Lead

Tags

NGSS.HS-PS3-4

Why did the metal feel colder than the book even though they were roughly the same temperature?

• The book took more energy/heat from its surroundings since it is thicker

• It was actually colder than the book, anything else stated is just a way to distract us

• The metal is an insulator, which means that it allowed for more cold to transfer to it from the environment

• The metal is a conductor, which allows for heat/energy to transfer from us to it much faster than the book.

Tags

NGSS.HS-PS3-4

There were 2 black blocks we put ice on last week, and one was a metal, while the other was a type of plastic/Styrofoam. Which one did ice melt faster on and why?

• Styrofoam-It is a conductor and allowed for better heat transfer

• Styrofoam-It allowed for cold to leave faster from the ice

• Metal-It is a conductor and allowed for better heat transfer

• Metal-It allowed for cold to leave faster from the ice

Tags

NGSS.HS-PS3-4

A block of ice is placed on a hot sidewalk. The ice melts because

• the energy from the ice flows to the sidewalk.

• the energy from the sidewalk flows to the ice.

• convection currents flow between the ice and the sidewalk

• radiation flows between the ice and the sidewalk

Tags

NGSS.HS-PS3-4

Energy cannot be created or destroyed, it only transforms or gets transferred to another object

• True

• False