Energy Transfer Problems

If two objects have different temperatures when they come in contact, heat will flow from the warmer object to the cooler one UNTIL ____________

• one reaches a temperature of zero

• they both have an equal temperature

• one runs out of energy

Tags

NGSS.HS-PS3-4

A sample of iron receives 50. J of heat energy that raises the temperature of the iron by 25.0°C. If iron has a specific heat of 0.10 J/g°C, what is the mass of the iron sample?

• 25g

• 30.g

• 20.g

• 50.g

The movement of thermal energy from an object at a higher temperature to an object at a lower temperature is called ____________.

• thermal
• expansion
• temperature
• heat

Tags

NGSS.HS-PS3-4

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.

Tags

NGSS.HS-PS3-4

How much energy is required to heat up 12.0kg of copper from 10.0 °C to 120. °C? The specific heat capacity of copper is 390 J/kg °C. (Copper does not go through a phase change at these temperatures)

• 46800 J

• 561600 J

• 514800 J

Tags

NGSS.HS-PS3-2

NGSS.HS-PS3-4

Calculate the amount of energy required to melt 35.0 grams of ice at its normal melting point.

H_fus = 80.0 cal/g, H_vap = 560.0 cal/g, C_p = 1.00 cal/g ºC

• 19,600 cal

• 35.0 cal

• 2,800 cal

• 1,570,000 cal

Tags

NGSS.HS-PS3-1

How many calories are required to boil 75 grams of water at its normal boiling point?

H_f = 80.0 cal/g, H_v = 560.0 cal/g, C_p = 1.00 cal/g ºC

(Do not worry about significant figures)

• 6,000 cal

• 3,360,000 cal

• 42,000 cal

• 7.46 cal

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-2

NGSS.HS-PS3-4

How much energy is required to completely boil 150. g of water at an initial temperature of 10^o C? Use C = 4.184 J/g^oC for water, and H_vap = 2260 J/g.

• 56,000 J

• 339,000 J

• 395,000 J

• 385,000 J

Tags

NGSS.HS-PS3-1

NGSS.HS-PS3-4

Calculate the specific heat of an unknown substance if 100.0 g of the substance at 200.0 °C reaches an equilibrium temperature of 27.10 °C when it is placed in 75.0 g of water at an initial temperature of 20.00 °C

(Specific heat of water is 4.18 J/g°C)

• 0.111 J/g°C

• 1.29 J/g°C

• 0.129 J/g°C

• 22225.85 J

Tags

NGSS.HS-PS3-4

Heat transfers from an area of (a)   temperature to an area of (b)   temperature.

• high to low
• low to high
• high to high

Tags

NGSS.HS-PS3-4