To calculate the percent error, use the formula |(Experimental Value - Accepted Value) / Accepted Value| x 100%. Reasons for a difference from the accepted value of heat of vaporization can include measurement errors or varying experimental conditions. Compute the class average of Hv to compare individual and class percent errors.
To calculate the percent error of a value from the accepted value, you first need to know the formula from Table T of your reference tables. Given that the student's measured heat of vaporization (Hv) differs from the accepted heat of vaporization, a percent error can elucidate the degree of this difference.
The formula for percent error is: Percent Error = |(Experimental Value - Accepted Value) / Accepted Value| x 100%
After plugging in the values into the formula: Percent Error = |(Measured Hv - 2260 J/g) / 2260 J/g| x 100%
To explain why the measured value of heat of vaporization differs from the accepted value, one could consider experimental errors, inaccuracies in measurement, or environmental conditions affecting the experiment. To determine the class average heat of vaporization, compile each group's Hv data provided by the teacher and calculate the mean.
Then, use the same percent error formula to find the percent error of the class average and compare it with the individual group's error to understand the variation.
Measuring the heat of vaporization requires energy measurements during phase changes which might explain the use of two beakers in the student's experiment scenario, as this could be a method to minimize heat loss and improve accuracy.