Specific Heat Capacity laboratory

Specific Heat Capacity: Heating Up

Purposes

To determine the specific heat capacity of various substances
To potentially identify materials by their specific heat capacity

Set Up

Obtain a thermometer, two styrofoam cups, and an object. Some of the objects which are using might include

nut            coral      silver cylinder
fishing mass   basalt     pair of brown cylinders
golden cube    grey cube  dented cube w/ square handle

Measurements

Description of object:	_{_________________}
The mass of the styrofoam cup	m_c	__________
The mass of the styrofoam cup with water	m_c+w	__________
The mass of the water m_c+w - m_c	m_w	__________
The mass of the object	m_x	__________
The start temperature of the object	t_x	__________
The start temperature of the water	t_i	__________
The highest final temperature of the water and object	t_f	__________

Procedure

Put the object in the boiling water.
Return water to boil.
Wait two minutes.
Rapidly transfer the object to the cup with water.
Cap the cup with the second cup and water and watch the temperature rise.
Record the highest temperature reached by the object and the water in the table above.

Calculations

Note that the specific heat capacity of water, c_w, is 1 calorie/(gram ·°C)

First law of thermodynamics: Energy is conserved. Heat is conserved. The object cooled down. The water warmed up. The object lost heat. The water gained heat. The heat lost by the object to the water is equal to the heat gained by the water. Heat is measured in calories. The letter Q is used for heat in calories.

Q_{lost by object} = Q_{gained by water}

m_xc_x[t_x - t_f] = m_wc_w[t_f-t_i]

(  m_x  )c_x[t_x -(  t_f  )] =( m_w  )(c_w)[( t_f    )-(    t_i    )]
(      )c_x[t_x -(      )] =(     )(1)[(       )-(          )]

Solve for c_x, the specific heat capacity of the object.

c_x = ___________

After performing the experiment on one material, obtain a second material by trading objects with another group. Make the same basic measurements, calculations, and report the result.

Description of second object:	_{_________________}
The mass of the styrofoam cup	m_c	__________
The mass of the styrofoam cup with water	m_c+w	__________
The mass of the water m_c+w - m_c	m_w	__________
The mass of the object	m_x	__________
The start temperature of the object	t_x	__________
The start temperature of the water	t_i	__________
The highest final temperature of the water and object	t_f	__________

(  m_x  )c_x[t_x -(  t_f  )] =( m_w  )(c_w)[( t_f    )-(    t_i    )]
(      )c_x[t_x -(      )] =(     )(1)[(       )-(          )]

c_x = ___________

Use the following table, if appropriate, to make an educated guess as to the materials you were working with if you were working with a metal. You can use density to guide you when in doubt. The density is the mass divided by the volume. The volume of a cube is length×width×height, the volume of a cylinder is p×(radius)²×Length

material	s.h.c. in cal/(g ·°C)	Density g/cm3
aluminum	0.215	2.7
basalt	0.24*
brass	0.092	8.4
copper	0.092	8.96
glass, crown	0.161	2.5
iron	0.107	7.87
lead	0.031	11.3
magnesium	0.245	1.74
steel	0.107	7.8
zinc	0.093	7.14

* Based on experimental data taken in physical science laboratory.

If you can determine the material, then work out the percentage error for your experiment.

Do the homework on page 45 of the lab book.

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