Uncertainty in measuring time was ±0. 01s according to the stopwatch but while measuring mass you have to first look at the time in stopwatch and then the mass in the electronic balance and because humans cannot react instantly it is estimated to be ±1s. Uncertainty in measuring mass of the water was ±0. 1g because it was measured using a weighing machine with the ±0. 1g uncertainty. The graph of mass of water evaporated over time is linear because the best fit line passes through all error bars.
From the calculations the specific latent heat of vaporization of water is calculated to be 2500 J/g ±60 J/g. The literature value of specific latent heat of vaporization of water is 2260 J/g, which is quite low. The total percent error is 10. 6% and the total percent uncertainty is 2. 5% which is quite low compared to the percentage error. 2. 5% uncertainty means the final result can be ±2. 5% off. That means the total error caused by uncertainties is 2.5%, rest is from systematic errors.
One of the biggest systematic errors could be the heat loss from the water to the atmosphere. A well-insulated plastic kettle was used to boil the water so there will be minimum heat loss from water to kettle and kettle to surroundings. If the heat is lost to the surroundings from water, it means that the power supplied by the kettle is not completely used to boil water as it is lost in the surrounding so the power supplied is less than 1000W.
While recording the mass of water, the mass of the water in the electronic balance was not constantly decreasing. Sometimes it increased, sometimes it decreased slowly and sometimes rapidly and because of this there was a high error in collecting data. An electronic balance with high mass capturing should have been used for better results. The electronic balance used did not have a wide base and the kettle used to boil water was overturning it which also can result in high error. An electronic balance with wide base should be used for more accurate results.