Lab Monday 3March2014

V vs. T for a Gas (Charles’ Law l)

 The syringe is placed into the flask and initial volume of the flask is recorded by taking a measurement of the mass and multiplying it by the density. The flask was placed into a bath of room temperature water  and volume of the syringe was recorded. The Temperature was recorded in logger pro. This was done so we can create three sets of data points to graph the relationship between Volume and Temperature and find the coefficient of their linear relationship.

This is a picture of the flask in a hot water bath and it illustrated how when the temperature increased the volume of the syringe increased. The opposite occurred for the ice bath, the volume decreased with a decrease in temperature.

 We expect that the relationship between volume and temperature is linear and our prediction is seen in this graph. The number of grams used to fill the flask to the stopper was determined on a analytical balance to be 142.1 g or 142.1 cc.  The data we collected gave us three points we can plot on a V vs T graph. One ordered pair for initial conditions at room temperature, cooling, and heating.

The reason the pressure of the air remains constant even though the volume changes is due to their inversely proportional relationship with volume and directly proportional relationship with temperature. P=(constant ) T/V as the volume and temperature change the pressure remains the same this can be seen when the ideal law is manipulated by dividing by the volume.  

V and T are linearly related and the slope of this graph was calculated in excel to be 0.312.

To understand the units of the slope we can manipulate the ideal gas law as seen above. We find the units of the coefficient to be 0.312 cc/K.