Thermochemistry Week #2 2024

Which description defines heat?

• total energy of an object or substance

• change in the temperature of a substance in degrees Celsius

• energy transferred between objects at different temperatures

• average kinetic energy of the particles that make up a substance

Tags

NGSS.HS-PS3-4

Using the heat equation, what would the formula look like if we were solving for change in temperature?

• q m = ∆T C

• q / (m C)  =  ∆T

• q m / C  =  ∆T

• m C q  =  ∆T

The symbol for specific heat is .......

• c

• q

• m

• T

If the specific heat of water is 4.18 J/g∙°C, how much heat is required to increase the temperature of 1,200 g of water from 23 °C to 39 °C?

• -80,256 J

• 80.256 J

• 80,256 J

• -80.256 J

How much energy is required to raise 85.36 g of water from 18.5^oC to 60.3^oC?

• 21500 J

• 6610 J

• 14900 J

• 85400 J

The temperature of a 6.0 g sample of glass changed from 20.0°C to 45.0°C when it absorbed 550 J of heat. What is the specific heat of this glass?

• 0.27 J/g °C

• 3.7 J/g °C

• 130 J/g °C

• 12 J/g °C

Calorimetry Question:
A piece of metal with a mass of 32.8 g is heated to 100.5°C and dropped into 138.2 g of water at 20.0°C.  The final temperature of the system is 30.2°C.  What is the specific heat capacity of the metal?

• 2.56 J/g°C

• 0.391 J/g°C

• 5.29 J/g°C

• 3.50 J/g°C

A metal cube at temperature of 70°C is immersed in water at temperature of 20°C.

• The metal loses more heat than the water gains.

• The metal loses less heat than the water gains.

• The metal loses the same amount of heat that the water gains.

If heat is absorbed and the temperature of the material rises....

• q is negative, and its endothermic process

• q is positive and it is an endothermic process

• q is negative and it is an exothermic process

• q is positive and it is an exothermic process.

If heat is release and the temperature of the material decreases....

• q is negative, and its endothermic process

• q is positive and it is an endothermic process

• q is negative and it is an exothermic process

• q is positive and it is an exothermic process.