Thermochem Calculations

A kilocalorie (kcal) is the same as:

• a gram of fat

• kilojoule

• a food calorie

• the calories found in a head of lettuce

1 calorie is also equal to ________________________.

• 4.18 joules

• 1 joule

• 2 joules

• 3 conductors

What is the definition of CONDUCTION?

• When heat is transferred from objects like rays of light or electromagnetically.
• a  hot liquid or air that  expands, becomes less dense, and rises or becomes more dense, and sinks.
• When heat transfers from objects that are touching.
• When heat transfers through the heater or AC in your house.

Tags

NGSS.MS-PS1-4

The earth receives heat energy from the sun by _______________, which is the transfer of energy as electromagnetic waves?

• radiation
• convection
• conduction
• greenhouse effect

The transfer of heat energy by direct contact, or touch, is __________________?

• radiation
• convection
• conduction
• greenhouse effect

ΔH value in an endothermic reaction is a positive number.

• True
• False

Tags

NGSS.HS-PS1-4

 _?_  is the amount of energy required to raise the temperature of 1 gram of any substance 1^oC.

• Specific heat
• A calorie
• Thermal energy
• Conduction

As 120 g of hot milk cools in a mug, it transfers 20, 000 J of heat to the environment. What is the temperature change of the milk? The specific heat of milk is 2.6 J/g·°C. (Q=mcΔT)

• 64 °C
• 1.56 °C
• 640 °C
• cannot be determined

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-4

If 100 g of aluminum at 145ºC gains 6,800 J of heat, what is the final temperature (T_final) of the aluminum? Aluminum has a specific heat of 0.897 J/gºC. (Q=mcΔT)

• -69°C
• 0.52°C
• 221°C

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-4

The SI units J/g°C measures

• Specific heat

• mass

• temperature

• heat energy

Tags

NGSS.MS-PS3-4