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Specific Heat Capacity Practice Problems by KGtyRV

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									                      Characteristics of Matter #1
                                                                          6. A 100 grams piece of metal increases its temperature from 20ºC to
                                                                          60ºC when 2500 Joules of energy are added to it. What is the specific
1. How much energy is required to increase the temperature of 150         heat capacity of this metal?
grams of water from 20ºC to 90ºC?




2. What is the mass of an iron skillet if its temperature increases       7. What is the mass of an aluminum pan if it requires 2000 Joules of
250ºC when 15000 J of energy is added to it?                              energy to increase its temperature 20ºC?




3. How much will the temperature of a 75 g silver fork increase if 2000   8. How much energy is given off by a 1500g iron pot as it cools from
J of energy are added to it?                                              320ºC to 25ºC?




4. If the initial temperature of the fork in the preceding problem is     9. A cup of tea can be consumed without burning one's tongue when its
28ºC, what is the new temperature after it has been heated?               temperature is 80ºC. Assuming that the specific heat of tea is basically
                                                                          the same as the water from which it is made, how much energy is
                                                                          absorbed by the body of the person who drinks a 125 g cup of tea as it
                                                                          cools in his stomach to a body temperature of 37ºC?




5. A child with the body temperature of 98ºC picks up a 20 g piece of
aluminum at room temperature (25ºC). He puts this piece of aluminum in
his pocket and eventually it warms up to his body temperature. How much
energy did his body lose by warming this piece of aluminum?
                     Characteristics of Matter #2
                                                                           5. The density of turpentine is 0.868 g/ml. What is the mass of 250.
1. An object with a mass of 50.00 grams and volume of 100 mls is placed    mls?
in water. What is the density of this object? If the density of water is
1.00 g/cm3, will this object float?

                                                                                                         Matter Vocab

                                                                           Place the following in one of four categories: mixture, solution, pure
                                                                           element, pure compound.
                                                                           Table sugar:________________________
2. A cube has a mass of 2.4 kg. Its dimensions are 4cm x 4cm x 4cm.
What is its density?                                                       Water: ________________________

                                                                           Coca-cola in a can: ________________________

                                                                           Vegetable soup: ________________________

                                                                           A penny: ________________________
3. An object of unknown volume and a mass of 25.0 g is placed in a
graduated cylinder filled with 3.5 mls of water. The water level in the    Oxygen: ________________________
graduated cylinder rises to 21.5 mls when the object is completely
submerged. What is the volume of the object? What is the density of        Air: ________________________
the object? Will the object float?
                                                                           Salt water: ________________________

                                                                           Sea water: ________________________

                                                                           Helium: ________________________

4. Mercury has a density of 13.6 g/cm3. If I need 25.0 grams of            Of the following, circle those that are chemical changes and underline
mercury, how many milliliters should I pour?                               those that are physical changes.
                                                                           melting butter          baking brownies       boiling water

                                                                           freezing alcohol       popping popcorn         melting steel

                                                                           shaking Sprite         mixing vinegar/baking soda to generate bubbles
               Characteristics of Matter Practice Test                         6. What is the volume of a piece of aluminum if it has a mass of 125
                                                                               grams?
1. How much energy is required to increase the temperature of a 250 g
iron pot from 28ºC to 190ºC?

                                                                               7. How much energy is required to heat 200 g water from room
                                                                               temperature (25ºC) to boiling (100ºC)?

2. What is the mass of an copper skillet if its temperature increases
150ºC when 12000 J of energy are added to it?
                                                                               8. List 5 physical characteristic of matter.




                                                                               9. List 3 chemical characteristics of matter.
3. 3000 J of energy are added to a 135 g silver spoon. If the original
temperature of the spoon is 26ºC, what is the new temperature of the
spoon after the energy is added?

                                                                               10. List four examples of a physical change.




4. When 878 J of energy are added to a 125 g piece of metal, the               11. List four examples of a chemical change.
temperature of the metal increases from 22ºC to 40ºC. What is the
specific heat of this metal? What is the identity of this metal?


                                                                                                                           Densities of Common Metals
                                                                            Common Specific Heat Capacities
                                                                                                                          Aluminum          2.71 g/cm3
                                                                            Aluminum        .91 J/gC
                                                                                                                          Brass             8.5 g/cm3
                                                                            Brass           .377 J/gC
                                                                                                                          Gold              19.3 g/cm3
                                                                            Copper          .39 J/gC
5. What is the density of a piece of metal if it has a mass of 28.0 grams                                                 Iron              7.85 g/cm3
                                                                            Iron            .46 J/gC
and a volume of 3.18 mL? What is this metal?                                                                              Nickel            8.8 g/cm3
                                                                            Nickel          .54 J/gC
                                                                                                                          Platinum          21.4 g/cm3
                                                                            Tin             .21 J/gC
                                                                                                                          Silver            10.5 g/cm3
                                                                            Silver         .24 J/gC
                                                                                                                          Tin               7.28 g/cm3
                                                                            Water          4.184 J/gC
                                                                                                                          Titanium          4.5 g/cm3
                                                                                                                                      o
HONORS Lab 1: Specific Heat Capacity and Density                                Assume specific heat capacity of water to be 4.184J/g C.
                                                                                Assume all the heat lost by the hot metal is transferred to the cold water.
of an Unknown Metal                                                             Assume the accepted value of specific heat capacity of iron to be 0.45J/g C.
                                                                                                                                                            o

                                                                                Assume the accepted value of specific heat capacity of copper to be
Purpose To calculate the specific heat capacity and density of a metal and               o
                                                                                0.385J/g C.
to use this information to identify the metal.                                  Assume the accepted value of specific heat capacity of aluminum to be
                                                                                       o
                                                                                0.89J/g C.
Apparatus 250mL beaker, 2 coffee cups, 100mL measuring cylinder, hot
plate, tongs, 2 thermometers, balance                                           Data Tables

Chemicals Water, sample of metal                                                                                   TABLE A

Procedure                                                                       Mass of metal sample
                                                                                Initial temperature of water in coffee
1. Place the metal sample on the balance and record the mass in table A.        cup calorimeter
2. Using the measuring cylinder add exactly 120mL of water to a “double         Temperature of hot water (metal)
coffee cup calorimeter”. Using a thermometer record the temperature of the      Initial volume of water in graduated
water in table A and in table B. Set it aside.                                  cylinder
                                                                                Final volume of water in graduated
3. Fill a 250mL beaker approximately half full with water and place it on the
                                                                                cylinder with metal cylinder submerged
hot plate. Carefully add the metal sample. Adjust the hot plate to a medium-
high heat setting. Using another thermometer, monitor the temperature of the
                                                                                Water temperature in coffee cup calorimeter
water as it heats up and continue heating until the water temperature
reaches approximately 90 C.
                           o                                                       Time in seconds          Temperature
                                                                                           0
                                              o
4. When the water reaches approximately 90 C, turn off the hot plate and                  30
remove the beaker.                                                                        60
                                                                                          90
5. Using tongs, carefully transfer the metal sample from the hot water to the            120
“double coffee cup calorimeter”. At this point record the temperature of the             150
hot water in table A.                                                                    180
                                                                                         210
6. Slowly sir the contents of the “double coffee cup calorimeter”, recording             240
the temperature every 30 seconds in table B. Continue to record the                      270
temperature until a maximum temperature has been reached.                                300
                                                                                         330
7. Dry the piece of metal. Obtain a 100 ml graduated cylinder. Place about               360
30 mls of water in the graduated cylinder and record the exact volume to 0.1
mL in the data table. Carefully and slowly drop the metal into the cylinder
and record the new volume to 0.1 mL in the data table. Empty the graduated
cylinder and return the metal to the prep table.

Assumptions

Assume the temperature of the sample of metal is the same as the hot water.
Assume the density of water to be 1g/mL.
Conclusion/Calculation (Complete this after you have finished the lab.)

1. Using the following relationships calculate the specific heat capacity of the
metal and compare your result to the accepted value.

Heat gained by wate r= (mass of water) x (cp of water) x (temp change of water)

Heat lost from metal = (mass of metal) x (cp of metal) x (temp change of metal)


2. Calculate the density of the metal. d = m/v
Remember that you can determine the volume of the cylinder by the
displacement of water in the graduated cylinder (final volume - initial volume).

3. Identify two possible errors in your experiment.

4. Using a table of common densities and a table of common specific heats,
propose the cylinder's metal.

								
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