Lab 16: Specific Heat of a Metal

Lab 16

Specific Heat of a Metal

Shiva Senthil

7/31/17

Introduction

The purpose of this lab was to measure the specific heat of a metal and identify the metal. The lab consisted of heating up a piece of metal, then letting it cool in water and observing differences in temperature and using specific heat of water to solve for the specific heat of the metal.

Data

Calculations

The measurements needed to calculate the specific heat are q, the amount of energy transferred; m, the mass of the metal; and ΔT, the change in temperature of the metal. To find q, we must first find the energy the water gained.

With the data from the lab, we can calculate m and ΔT for the water. C is constant for water, and is defined at 4.18J/g°C. We then use the formula:

We can plug in the values on the right side, as they have all been found:

Solving for q:

We get that 1800 joules transferred from the hot metal to the water.

Thus, we use -1800 joules as q for the metal. The mass and change in temperature can be calculated from the data.

To solve for c, the specific heat, we use this formula derived from the previous formula:

Then, we plug in the values:

Solving for c, then converting to kilojoules:

We get the specific heat of the metal is 356J/kg°C.

According to the given values, this is closest to brass, which has a specific heat of 380J/kg°C.

Thus the metal was identified as brass.

Errors

There were many opportunities for error in this lab. The thermometer was only accurate to the nearest degree, so the number of significant figures was only three. Also, the environment was not completely closed, as the hole for the thermometer allows for some vapor to escape. Many of the metals had similar specific heats, so small errors could have changed the identity of the metal.