You can find the amount of moles of a compound or element by dividing their mass by their molar mass.
Standard temperature and pressure are the following: 273 kelvin is standard temperature, while 1 atm is standard pressure. with an R value of 0.0821
percentage error determines how far you were from the theoretical answer to something. You can get this value by dividing you answer by the theoretical answer and then turning the result into a percentage.
The law of conservation of matter states that matter can't be created or destroyed.