Question

Find out how the specific heats of gases, liquids, and solids are determined in national laboratories. Describe the experimental apparatus and the procedures used.

Answer 1

Determination of specific heat of solid and liquid and gases:

 

Theory:

In apparatus named as hypsometer, a sample of solid is to be heated above the room temperature( a fixed temperature) and then it is added to the cold water in calorimeter. In this process, the heat lost by solid is equal to the heat gained by water and calorimeter.

 

Apparatus:

Calorimeter, Hypsometer, thermometer, Burner, Wooden stand,Boiler,Stirrer, lid and other experimental apparatus.

Fig: Determination of specific heat of solid and liquid

 

Method:

 

Step1 : First of all take two thermometer in beaker to note down their initial reading.

 

Step2: Put one thermometer in copper tube of hypsometer having powde of solid. Pour sofficient amount of water in hypsometer and flame it by means of burner.

 

Step3: Measure the weght of calorimeter including stirrer and lid and note down the reading.

 

Step 4: Pour water in half of the calorimeter at 5-8 degree celcius below the room temperature. Measure its weight againa and note down the reading.

 

Step 5: Keep heating the hypsometer about 10 minute untill the temperature of solid becomes steady.

 

Step 6: Record the temperature of water in calorimeter and transfer the solid from hypsometer to calorimeter. Keep stirring the mixture of solid and water and record the final temperature of mixture.

 

Step 7: Finally remove the thermometer from calorimeter and measure the weight of calorimeter with stirr, lead and its content.

 

Step 8: To determine the specific heat of given liquid, take liquid whose specific heat is to be determined instead of cold water and repeat the procedure of determination of specific heat of solid. Now we have already determined the specific heat of solid for rest of procedure.

 

Result:

The heat lost by solid is equal to the heat gained by water and calorimeter.

 

Specific heat of gases can be determined by this procedure but there are any errors for gases.

The heat lost by solid is equal to the heat gained by water and calorimeter.