50 terms

heat

The energy transferred due to a temperature difference.

joule

The SI unit of energy.

calorie

The English unit of energy which is equal to 4.184 joules.

kilocalorie

Food equivalent to 1000 calories or 1-Cal.

specific heat

The heat needed to raise the temperature of 1 grams of a substance 1 degree Celsius.

exothermic

A chemical reaction that gives off heat.

calorimeter

A scientific device used to measure the amount of energy given off or absorbed during a physical or chemical change.

q= mc(delta t)

Formula used in specific heat problems to solve for heat gained or lost.

C(subscript p)

Variable used for specific heat.

(delta)t

Variable meaning "change in" temperature.

q

Variable that stands for heat energy.

mc(delta t) = mc(delta t)

Formula used when mixing something hot with something cold.

m(subscript 2)

Variable that means the second substance.

t(subscript 1)

Variable that means the temperature of the first substance.

equilibrium

A situation in which there is no net gain or loss of a substance.

melting point

The temperature and pressure conditions in which the solid phase changes to the liquid phase.

freezing point

The temperature and pressure conditions at which the liquid phase changes into the solid phase.

boiling point

The temperature and pressure conditions at which the liquid state changes into the vapor state.

condensation

The temperature and pressure conditions at which the vapor state changes into the liquid state.

enthalpy of fusion

The amount of heat needed to melt 1 gram of a substance at its melting point.

enthalpy of vaporization

The amount of heat needed to vaporize 1 gram of a substance at its boiling point.

endothermic

A chemical reaction that absorbs heat and gets colder.

480

2008 joules = ____________ calories

8.37x10(exponent 6)

2000-Calories = __________ joules

10,000

10,000,000 calories = ____________ Calories

1.63

6800 Joules = ____________Calories

328.4

78.5 calories = __________ joules

761,488-J

How many joules of heat is required to raise the temperature of 2600-g of water from 25 degrees Celsius to 95 degrees Celsius?

11,696-J

If aluminum's specific heat is 0.9025 J/g(C), how much heat is required to raise 324-grams of Al from 10 degrees Celsius to 50 degrees Celsius?

939.85-g

If 15,ooo-J of heat is required to heat a sample of cobalt whose Cp=0.42 J/g(C), from 20 degrees Celsius to 58 degrees Celsius. What is the mass of the cobalt in grams?

22.12 degrees Celsius

If 35,000-J of heat is removed from 1000 grams of iron at 100 degrees celsius, what is the final temperature given that the specific heat of iron is 0.4494 J/g(C)?

24,920-J

If the specific heat of lead is 0.1276 J/g(C), how much heat energy is necessary to raise 700 grams of lead from 21 to 300 degrees Celsius?

26.6-Celsius

If 50-g of aluminum with a specific heat of 0.9025 J/g(C) is at 100 degrees Celsius and dropped into 120-grams of water, whose density you have memorized, at a temperature of 20 degrees Celsius. What is the final temperature of the system?

C(subscript p) = 0.4404 J/g(C)

An unknown metal of mass 100-grams is heated in boiling water and after 5 minutes is dropped into a 200-grams of water, whose specific heat you memorized, at a temperature of 20 degrees Celsius. Equilibrium was reached in the system when the temperature became 24 degrees Celsius. What is the specific heat of the unknown metal?

55.6-Celsius

25-g of iron at a specific heat of 0.4494-J/g(C) and a temperature of 98 degrees Celsius is dropped into 50-g of water at 26 degrees Celsius. What is the final temperature of the system when it reaches equilibrium?

256,512-J

How much heat is required to melt 768 grams of ice at its melting point? The enthalpy of fusion of ice is 334-J/g.

31,843-J

How much heat is required to take 50-grams of ice at -15 degrees Celsius to liquid water at 65 degrees Celsius? The specific heat of ice is 2.06-J/g(C) and the enthalpy of fusion of ice is 334-J/g and you memorized the specific heat of liquid water.

784,000-J

How much heat is required to heat 300-g of water from 20 degrees Celsius to steam at 110 degrees Celsius? The enthalpy of vaporization of water is 2260-J/g and the specific heat of steam is 2.02-J/g(C) and you memorized the specific heat of liquid water.....so I don't need to list it.

77,658-J

Given that the The enthalpy of vaporization of water is 2260-J/g and the specific heat of steam is 2.02-J/g(C) and the enthalpy of fusion of water is 334-J/g and the specific heat of ice is 2.06-J/g(C), and that you memorized the specific heat of liquid water, what is the amount of heat needed to take 25-g of ice at -25 degrees Celsius to steam at 121 degrees Celsius?

-21,930-J

How much heat is removed from 50-g of liquid water at 20 degrees Celsius to ice at 0-degrees Celsius, given the specific heat of water is memorized by you and the enthalpy of fusion of water is 334-j/g?

4.184-J/g(C)

What is the specific heat of liquid water?

212,160-J, 635.2-g ice

First, figure how much energy is removed from 2000-cm(cubed) of Pepsi whose density is 1.02-g/cubic cm to lower the temperature from 25 to 0 degrees Celsius and the enthalpy of fusion of ice is 334-J/g. The specific heat of Pepsi is 4.16-J/g(C). The final answer, is how much ice is required to melt to lower the temperature of the system?

From hot to cold.

What direction does heat flow?

2.06 J/g(C)

What is the specific heat of ice?

2.02 J/g(C)

What is the specific heat of steam?

Final temperature

T(subscript f) means ___________?

potential

When at the melting point, all the energy supplied is in the formed called __________, because the temperature does not change and only a change of state takes place.

kinetic

Whenever you have delta-t as part of the equation, the energy supplied is in the form of ________ because there is a temperature change.

heat

The most common form of energy transfer is the liberation or absorption of ________.

False, it is the Calorie.

True of False? The unit used to measure the energy of food is called the calorie.