Measurement of the specific heat capacity of a metal or water by a mechanical method

Physics Experiments

Apparatus

Copper calorimeter, copper rivets, beaker, boiling tube, lagging, thermometer accurate to 0.1°C, heat source and electronic balance.

Procedure

• Place some copper rivets in a boiling tube. Fill a beaker with water and place the boiling tube in it.

• Heat the beaker until the water boils. Allow boiling for a further five minutes to ensure that the copper pieces are 100°C.

• Find the mass of the copper calorimeter $m_{\text{cal}}$.

• Fill the calorimeter, one quarter full with cold water. Find the combined mass of the calorimeter and water and hence the mass of the water $m_w$ is $m_T - m_{\text{cal}}$.

• Record the initial temperature of the calorimeter plus water $θ_c$.

• Quickly add the hot copper rivets to the calorimeter, without splashing.

• Stir the water and record the highest temperature $θ_h$. The fall in temperature $Δθ$ of the copper rivets is 100°C - $θ_h$. The rise in temperature $Δθ_c$ of the calorimeter plus water is $θ_h - θ_c$.

• Find the mass of the calorimeter plus water plus copper rivets $m_T$ and hence find the mass of the rivets $m_{\text{cu}}$.

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Measurement of specific heat capacity of water by an electrical method

Physics Experiments

Results

Mass of the calorimeter: $m_{cal} =$

Mass of the calorimeter plus the water: $m_1 =$

Mass of the water: $m_w = m_1 - m_{cal} =$

Initial temperature of water: $θ_1 =$

Initial temperature of rivets: $100° C$

Initial temperature of calorimeter: $θ_1 =$

Final temperature of water: $θ_2 =$

Final temperature of rivets: $θ_2 =$

Rise in temperature of water: $Δθ_w = θ_2 - θ_1 =$

Rise in temperature of calorimeter: $Δθ_c = θ_2 - θ_1 =$

Fall in temperature of rivets: $Δθ_r = 100° C - θ_2$

Mass of calorimeter plus water plus rivets: $m_2 =$

Mass of rivets: $m_{cu} = m_2 - m_1$

Calculations

Assume that heat losses to the surroundings or heat gains from the surroundings are negligible.

Given that either the specific heat capacity of water cw or the specific heat capacity of copper cc is known, the other specific heat capacity can be calculated from the following equation:

Energy lost by copper rivets = energy gained by copper calorimeter + the energy gained by the water

$m_{cu}c_c Δθ_r = m_{cal}c_c Δθ_c + m_w c_w Δθ_w$

If cw is known, then cc can be calculated or alternatively if cc is known, cw can be found.